mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-11-04 18:05:06 +01:00
3068 lines
82 KiB
C
3068 lines
82 KiB
C
/***************************************************************************************
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* Genesis Plus
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* Video Display Processor (68k & Z80 CPU interface)
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*
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* Support for SG-1000, Master System (315-5124 & 315-5246), Game Gear & Mega Drive VDP
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*
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* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Charles Mac Donald (original code)
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* Copyright (C) 2007-2013 Eke-Eke (Genesis Plus GX)
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*
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* Redistribution and use of this code or any derivative works are permitted
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* provided that the following conditions are met:
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*
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* - Redistributions may not be sold, nor may they be used in a commercial
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* product or activity.
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*
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* - Redistributions that are modified from the original source must include the
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* complete source code, including the source code for all components used by a
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* binary built from the modified sources. However, as a special exception, the
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* source code distributed need not include anything that is normally distributed
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* (in either source or binary form) with the major components (compiler, kernel,
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* and so on) of the operating system on which the executable runs, unless that
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* component itself accompanies the executable.
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*
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* - Redistributions must reproduce the above copyright notice, this list of
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* conditions and the following disclaimer in the documentation and/or other
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* materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************************/
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#include "shared.h"
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#include "hvc.h"
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/* Mark a pattern as modified */
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#define MARK_BG_DIRTY(addr) \
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{ \
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name = (addr >> 5) & 0x7FF; \
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if(bg_name_dirty[name] == 0) \
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{ \
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bg_name_list[bg_list_index++] = name; \
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} \
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bg_name_dirty[name] |= (1 << ((addr >> 2) & 7)); \
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}
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/* VDP context */
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uint8 sat[0x400]; /* Internal copy of sprite attribute table */
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uint8 vram[0x10000]; /* Video RAM (64K x 8-bit) */
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uint8 cram[0x80]; /* On-chip color RAM (64 x 9-bit) */
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uint8 vsram[0x80]; /* On-chip vertical scroll RAM (40 x 11-bit) */
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uint8 reg[0x20]; /* Internal VDP registers (23 x 8-bit) */
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uint8 hint_pending; /* 0= Line interrupt is pending */
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uint8 vint_pending; /* 1= Frame interrupt is pending */
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uint16 status; /* VDP status flags */
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uint32 dma_length; /* DMA remaining length */
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/* Global variables */
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uint16 ntab; /* Name table A base address */
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uint16 ntbb; /* Name table B base address */
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uint16 ntwb; /* Name table W base address */
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uint16 satb; /* Sprite attribute table base address */
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uint16 hscb; /* Horizontal scroll table base address */
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uint8 bg_name_dirty[0x800]; /* 1= This pattern is dirty */
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uint16 bg_name_list[0x800]; /* List of modified pattern indices */
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uint16 bg_list_index; /* # of modified patterns in list */
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uint8 hscroll_mask; /* Horizontal Scrolling line mask */
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uint8 playfield_shift; /* Width of planes A, B (in bits) */
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uint8 playfield_col_mask; /* Playfield column mask */
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uint16 playfield_row_mask; /* Playfield row mask */
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uint16 vscroll; /* Latched vertical scroll value */
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uint8 odd_frame; /* 1: odd field, 0: even field */
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uint8 im2_flag; /* 1= Interlace mode 2 is being used */
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uint8 interlaced; /* 1: Interlaced mode 1 or 2 */
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uint8 vdp_pal; /* 1: PAL , 0: NTSC (default) */
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uint16 v_counter; /* Vertical counter */
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uint16 vc_max; /* Vertical counter overflow value */
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uint16 lines_per_frame; /* PAL: 313 lines, NTSC: 262 lines */
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int32 fifo_write_cnt; /* VDP writes fifo count */
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uint32 fifo_lastwrite; /* last VDP write cycle */
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uint32 hvc_latch; /* latched HV counter */
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const uint8 *hctab; /* pointer to H Counter table */
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/* Function pointers */
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void (*vdp_68k_data_w)(unsigned int data);
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void (*vdp_z80_data_w)(unsigned int data);
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unsigned int (*vdp_68k_data_r)(void);
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unsigned int (*vdp_z80_data_r)(void);
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/* Function prototypes */
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static void vdp_68k_data_w_m4(unsigned int data);
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static void vdp_68k_data_w_m5(unsigned int data);
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static unsigned int vdp_68k_data_r_m4(void);
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static unsigned int vdp_68k_data_r_m5(void);
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static void vdp_z80_data_w_m4(unsigned int data);
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static void vdp_z80_data_w_m5(unsigned int data);
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static unsigned int vdp_z80_data_r_m4(void);
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static unsigned int vdp_z80_data_r_m5(void);
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static void vdp_z80_data_w_ms(unsigned int data);
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static void vdp_z80_data_w_gg(unsigned int data);
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static void vdp_z80_data_w_sg(unsigned int data);
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static void vdp_bus_w(unsigned int data);
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static void vdp_fifo_update(unsigned int cycles);
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static void vdp_reg_w(unsigned int r, unsigned int d, unsigned int cycles);
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static void vdp_dma_68k_ext(unsigned int length);
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static void vdp_dma_68k_ram(unsigned int length);
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static void vdp_dma_68k_io(unsigned int length);
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static void vdp_dma_copy(unsigned int length);
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static void vdp_dma_fill(unsigned int length);
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/* Tables that define the playfield layout */
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static const uint8 hscroll_mask_table[] = { 0x00, 0x07, 0xF8, 0xFF };
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static const uint8 shift_table[] = { 6, 7, 0, 8 };
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static const uint8 col_mask_table[] = { 0x0F, 0x1F, 0x0F, 0x3F };
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static const uint16 row_mask_table[] = { 0x0FF, 0x1FF, 0x2FF, 0x3FF };
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static uint8 border; /* Border color index */
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static uint8 pending; /* Pending write flag */
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static uint8 code; /* Code register */
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static uint8 dma_type; /* DMA mode */
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static uint16 addr; /* Address register */
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static uint16 addr_latch; /* Latched A15, A14 of address */
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static uint16 sat_base_mask; /* Base bits of SAT */
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static uint16 sat_addr_mask; /* Index bits of SAT */
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static uint16 dma_src; /* DMA source address */
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static uint16 dmafill; /* DMA Fill setup */
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static uint32 dma_endCycles; /* 68k cycles to DMA end */
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static uint32 fifo_latency; /* CPU access latency */
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static int cached_write; /* 2nd part of 32-bit CTRL port write (Genesis mode) or LSB of CRAM data (Game Gear mode) */
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static uint16 fifo[4]; /* FIFO buffer */
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/* set Z80 or 68k interrupt lines */
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static void (*set_irq_line)(unsigned int level);
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static void (*set_irq_line_delay)(unsigned int level);
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/* Vertical counter overflow values (see hvc.h) */
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static const uint16 vc_table[4][2] =
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{
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/* NTSC, PAL */
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{0xDA , 0xF2}, /* Mode 4 (192 lines) */
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{0xEA , 0x102}, /* Mode 5 (224 lines) */
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{0xDA , 0xF2}, /* Mode 4 (192 lines) */
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{0x106, 0x10A} /* Mode 5 (240 lines) */
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};
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/* DMA Timings (number of access slots per line) */
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static const uint8 dma_timing[2][2] =
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{
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/* H32, H40 */
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{16 , 18}, /* active display */
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{167, 205} /* blank display */
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};
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/* DMA processing functions (set by VDP register 23 high nibble) */
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static void (*const dma_func[16])(unsigned int length) =
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{
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/* 0x0-0x3 : DMA from 68k bus $000000-$7FFFFF (external area) */
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vdp_dma_68k_ext,vdp_dma_68k_ext,vdp_dma_68k_ext,vdp_dma_68k_ext,
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/* 0x4-0x7 : DMA from 68k bus $800000-$FFFFFF (internal RAM & I/O) */
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vdp_dma_68k_ram, vdp_dma_68k_io,vdp_dma_68k_ram,vdp_dma_68k_ram,
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/* 0x8-0xB : DMA Fill */
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vdp_dma_fill,vdp_dma_fill,vdp_dma_fill,vdp_dma_fill,
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/* 0xC-0xF : DMA Copy */
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vdp_dma_copy,vdp_dma_copy,vdp_dma_copy,vdp_dma_copy
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};
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/*--------------------------------------------------------------------------*/
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/* Init, reset, context functions */
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/*--------------------------------------------------------------------------*/
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void vdp_init(void)
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{
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/* PAL/NTSC timings */
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lines_per_frame = vdp_pal ? 313: 262;
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/* CPU interrupt line(s)*/
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if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
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{
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/* 68k cpu */
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set_irq_line = m68k_set_irq;
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set_irq_line_delay = m68k_set_irq_delay;
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}
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else
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{
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/* Z80 cpu */
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set_irq_line = z80_set_irq_line;
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set_irq_line_delay = z80_set_irq_line;
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}
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}
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void vdp_reset(void)
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{
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int i;
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memset ((char *) sat, 0, sizeof (sat));
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memset ((char *) vram, 0, sizeof (vram));
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memset ((char *) cram, 0, sizeof (cram));
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memset ((char *) vsram, 0, sizeof (vsram));
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memset ((char *) reg, 0, sizeof (reg));
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addr = 0;
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addr_latch = 0;
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code = 0;
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pending = 0;
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border = 0;
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hint_pending = 0;
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vint_pending = 0;
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dmafill = 0;
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dma_src = 0;
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dma_type = 0;
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dma_length = 0;
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dma_endCycles = 0;
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odd_frame = 0;
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im2_flag = 0;
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interlaced = 0;
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fifo_write_cnt = 0;
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fifo_lastwrite = 0;
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cached_write = -1;
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ntab = 0;
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ntbb = 0;
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ntwb = 0;
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satb = 0;
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hscb = 0;
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vscroll = 0;
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hscroll_mask = 0x00;
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playfield_shift = 6;
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playfield_col_mask = 0x0F;
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playfield_row_mask = 0x0FF;
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sat_base_mask = 0xFE00;
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sat_addr_mask = 0x01FF;
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/* reset pattern cache changes */
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bg_list_index = 0;
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memset ((char *) bg_name_dirty, 0, sizeof (bg_name_dirty));
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memset ((char *) bg_name_list, 0, sizeof (bg_name_list));
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/* default HVC */
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hvc_latch = 0x10000;
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hctab = cycle2hc32;
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vc_max = vc_table[0][vdp_pal];
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v_counter = lines_per_frame - 1;
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/* default Window clipping */
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window_clip(0,0);
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/* default FIFO timings */
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fifo_latency = 214;
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/* reset VDP status (FIFO empty flag is set) */
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if (system_hw & SYSTEM_MD)
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{
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status = vdp_pal | 0x200;
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}
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else
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{
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status = 0;
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}
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/* default display area */
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bitmap.viewport.w = 256;
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bitmap.viewport.h = 192;
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bitmap.viewport.ow = 256;
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bitmap.viewport.oh = 192;
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/* default overscan area */
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if ((system_hw == SYSTEM_GG) && !config.gg_extra)
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{
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/* Display area reduced to 160x144 if overscan is disabled */
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bitmap.viewport.x = (config.overscan & 2) ? 14 : -48;
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bitmap.viewport.y = (config.overscan & 1) ? (24 * (vdp_pal + 1)) : -24;
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}
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else
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{
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bitmap.viewport.x = (config.overscan & 2) * 7;
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bitmap.viewport.y = (config.overscan & 1) * 24 * (vdp_pal + 1);
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}
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/* default rendering mode */
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update_bg_pattern_cache = update_bg_pattern_cache_m4;
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if (system_hw < SYSTEM_MD)
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{
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/* Mode 0 */
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render_bg = render_bg_m0;
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render_obj = render_obj_tms;
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parse_satb = parse_satb_tms;
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}
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else
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{
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/* Mode 4 */
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render_bg = render_bg_m4;
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render_obj = render_obj_m4;
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parse_satb = parse_satb_m4;
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}
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/* 68k bus access mode (Mode 4 by default) */
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vdp_68k_data_w = vdp_68k_data_w_m4;
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vdp_68k_data_r = vdp_68k_data_r_m4;
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/* Z80 bus access mode */
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switch (system_hw)
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{
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case SYSTEM_SG:
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{
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/* SG-1000 port access */
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vdp_z80_data_w = vdp_z80_data_w_sg;
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vdp_z80_data_r = vdp_z80_data_r_m4;
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break;
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}
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case SYSTEM_GG:
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{
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/* Game Gear port access */
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vdp_z80_data_w = vdp_z80_data_w_gg;
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vdp_z80_data_r = vdp_z80_data_r_m4;
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break;
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}
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case SYSTEM_MARKIII:
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case SYSTEM_SMS:
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case SYSTEM_SMS2:
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case SYSTEM_GGMS:
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{
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/* Master System port access */
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vdp_z80_data_w = vdp_z80_data_w_ms;
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vdp_z80_data_r = vdp_z80_data_r_m4;
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break;
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}
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default:
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{
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/* Genesis port access */
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vdp_z80_data_w = vdp_z80_data_w_m4;
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vdp_z80_data_r = vdp_z80_data_r_m4;
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break;
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}
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}
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/* SG-1000 specific */
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if (system_hw == SYSTEM_SG)
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{
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/* 16k address decoding by default (Magical Kid Wiz) */
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vdp_reg_w(1, 0x80, 0);
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/* no H-INT on TMS9918 */
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vdp_reg_w(10, 0xFF, 0);
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}
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/* Master System specific */
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else if ((system_hw & SYSTEM_SMS) && (!(config.bios & 1) || !(system_bios & SYSTEM_SMS)))
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{
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/* force registers initialization (only if Master System BIOS is disabled or not loaded) */
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vdp_reg_w(0 , 0x36, 0);
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vdp_reg_w(1 , 0x80, 0);
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vdp_reg_w(2 , 0xFF, 0);
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vdp_reg_w(3 , 0xFF, 0);
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vdp_reg_w(4 , 0xFF, 0);
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vdp_reg_w(5 , 0xFF, 0);
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vdp_reg_w(6 , 0xFF, 0);
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vdp_reg_w(10, 0xFF, 0);
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/* Mode 4 */
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render_bg = render_bg_m4;
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render_obj = render_obj_m4;
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parse_satb = parse_satb_m4;
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}
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/* Mega Drive specific */
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else if (((system_hw == SYSTEM_MD) || (system_hw == SYSTEM_MCD)) && (config.bios & 1) && !(system_bios & SYSTEM_MD))
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{
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/* force registers initialization (only if TMSS model is emulated and BOOT ROM is not loaded) */
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vdp_reg_w(0 , 0x04, 0);
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vdp_reg_w(1 , 0x04, 0);
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vdp_reg_w(10, 0xFF, 0);
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vdp_reg_w(12, 0x81, 0);
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vdp_reg_w(15, 0x02, 0);
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}
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/* reset color palette */
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for(i = 0; i < 0x20; i ++)
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{
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color_update_m4(i, 0x00);
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}
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color_update_m4(0x40, 0x00);
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}
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int vdp_context_save(uint8 *state)
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{
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int bufferptr = 0;
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save_param(sat, sizeof(sat));
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save_param(vram, sizeof(vram));
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save_param(cram, sizeof(cram));
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save_param(vsram, sizeof(vsram));
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save_param(reg, sizeof(reg));
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save_param(&addr, sizeof(addr));
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save_param(&addr_latch, sizeof(addr_latch));
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save_param(&code, sizeof(code));
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save_param(&pending, sizeof(pending));
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save_param(&status, sizeof(status));
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save_param(&dmafill, sizeof(dmafill));
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save_param(&hint_pending, sizeof(hint_pending));
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save_param(&vint_pending, sizeof(vint_pending));
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save_param(&dma_length, sizeof(dma_length));
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save_param(&dma_type, sizeof(dma_type));
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save_param(&dma_src, sizeof(dma_src));
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save_param(&cached_write, sizeof(cached_write));
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return bufferptr;
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}
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int vdp_context_load(uint8 *state)
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{
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int i, bufferptr = 0;
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uint8 temp_reg[0x20];
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load_param(sat, sizeof(sat));
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load_param(vram, sizeof(vram));
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load_param(cram, sizeof(cram));
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load_param(vsram, sizeof(vsram));
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load_param(temp_reg, sizeof(temp_reg));
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/* restore VDP registers */
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if (system_hw < SYSTEM_MD)
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{
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if (system_hw > SYSTEM_SG)
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{
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for (i=0;i<0x10;i++)
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{
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pending = 1;
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addr_latch = temp_reg[i];
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vdp_sms_ctrl_w(0x80 | i);
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}
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}
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else
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{
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for (i=0;i<0x08;i++)
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{
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pending = 1;
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addr_latch = temp_reg[i];
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vdp_tms_ctrl_w(0x80 | i);
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}
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}
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}
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else
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{
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for (i=0;i<0x20;i++)
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{
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vdp_reg_w(i, temp_reg[i], 0);
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}
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}
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load_param(&addr, sizeof(addr));
|
|
load_param(&addr_latch, sizeof(addr_latch));
|
|
load_param(&code, sizeof(code));
|
|
load_param(&pending, sizeof(pending));
|
|
load_param(&status, sizeof(status));
|
|
load_param(&dmafill, sizeof(dmafill));
|
|
load_param(&hint_pending, sizeof(hint_pending));
|
|
load_param(&vint_pending, sizeof(vint_pending));
|
|
load_param(&dma_length, sizeof(dma_length));
|
|
load_param(&dma_type, sizeof(dma_type));
|
|
load_param(&dma_src, sizeof(dma_src));
|
|
|
|
load_param(&cached_write, sizeof(cached_write));
|
|
|
|
/* restore FIFO timings */
|
|
fifo_latency = (reg[12] & 1) ? 190 : 214;
|
|
fifo_latency <<= ((code & 0x0F) < 0x03);
|
|
|
|
/* restore current NTSC/PAL mode */
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
status = (status & ~1) | vdp_pal;
|
|
}
|
|
|
|
if (reg[1] & 0x04)
|
|
{
|
|
/* Mode 5 */
|
|
bg_list_index = 0x800;
|
|
|
|
/* reinitialize palette */
|
|
color_update_m5(0, *(uint16 *)&cram[border << 1]);
|
|
for(i = 1; i < 0x40; i++)
|
|
{
|
|
color_update_m5(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Modes 0,1,2,3,4 */
|
|
bg_list_index = 0x200;
|
|
|
|
/* reinitialize palette */
|
|
for(i = 0; i < 0x20; i ++)
|
|
{
|
|
color_update_m4(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
color_update_m4(0x40, *(uint16 *)&cram[(0x10 | (border & 0x0F)) << 1]);
|
|
}
|
|
|
|
/* invalidate cache */
|
|
for (i=0;i<bg_list_index;i++)
|
|
{
|
|
bg_name_list[i]=i;
|
|
bg_name_dirty[i]=0xFF;
|
|
}
|
|
|
|
return bufferptr;
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* DMA update function */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
void vdp_dma_update(unsigned int cycles)
|
|
{
|
|
int dma_cycles, dma_bytes;
|
|
|
|
/* DMA transfer rate (bytes per line)
|
|
|
|
According to the manual, here's a table that describes the transfer
|
|
rates of each of the three DMA types:
|
|
|
|
DMA Mode Width Display Transfer Count
|
|
-----------------------------------------------------
|
|
68K > VDP 32-cell Active 16
|
|
Blanking 167
|
|
40-cell Active 18
|
|
Blanking 205
|
|
VRAM Fill 32-cell Active 15
|
|
Blanking 166
|
|
40-cell Active 17
|
|
Blanking 204
|
|
VRAM Copy 32-cell Active 8
|
|
Blanking 83
|
|
40-cell Active 9
|
|
Blanking 102
|
|
|
|
'Active' is the active display period, 'Blanking' is either the vertical
|
|
blanking period or when the display is forcibly blanked via register #1.
|
|
|
|
The above transfer counts are all in bytes, unless the destination is
|
|
CRAM or VSRAM for a 68K > VDP transfer, in which case it is in words.
|
|
*/
|
|
unsigned int rate = dma_timing[(status & 8) || !(reg[1] & 0x40)][reg[12] & 1];
|
|
|
|
/* Adjust for 68k bus DMA to VRAM (one word = 2 access) or DMA Copy (one read + one write = 2 access) */
|
|
rate = rate >> (dma_type & 1);
|
|
|
|
/* Remaining DMA cycles */
|
|
if (status & 8)
|
|
{
|
|
/* Process DMA until the end of VBLANK */
|
|
/* NOTE: DMA timings can not change during VBLANK because active display width cannot be modified. */
|
|
/* Indeed, writing VDP registers during DMA is either impossible (when doing DMA from 68k bus, CPU */
|
|
/* is locked) or will abort DMA operation (in case of DMA Fill or Copy). */
|
|
dma_cycles = (lines_per_frame * MCYCLES_PER_LINE) - cycles;
|
|
}
|
|
else
|
|
{
|
|
/* Process DMA until the end of current line */
|
|
dma_cycles = (mcycles_vdp + MCYCLES_PER_LINE) - cycles;
|
|
}
|
|
|
|
/* Remaining DMA bytes for that line */
|
|
dma_bytes = (dma_cycles * rate) / MCYCLES_PER_LINE;
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] DMA type %d (%d access/line)(%d cycles left)-> %d access (%d remaining) (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE,dma_type, rate, dma_cycles, dma_bytes, dma_length, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
|
|
/* Check if DMA can be finished before the end of current line */
|
|
if (dma_length < dma_bytes)
|
|
{
|
|
/* Adjust remaining DMA bytes */
|
|
dma_bytes = dma_length;
|
|
dma_cycles = (dma_bytes * MCYCLES_PER_LINE) / rate;
|
|
}
|
|
|
|
/* Update DMA timings */
|
|
if (dma_type < 2)
|
|
{
|
|
/* 68K is frozen during DMA from 68k bus */
|
|
m68k.cycles = cycles + dma_cycles;
|
|
#ifdef LOGVDP
|
|
error("-->CPU frozen for %d cycles\n", dma_cycles);
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
/* Set DMA Busy flag */
|
|
status |= 0x02;
|
|
|
|
/* 68K is still running, set DMA end cycle */
|
|
dma_endCycles = cycles + dma_cycles;
|
|
#ifdef LOGVDP
|
|
error("-->DMA ends in %d cycles\n", dma_cycles);
|
|
#endif
|
|
}
|
|
|
|
/* Process DMA */
|
|
if (dma_bytes > 0)
|
|
{
|
|
/* Update DMA length */
|
|
dma_length -= dma_bytes;
|
|
|
|
/* Process DMA operation */
|
|
dma_func[reg[23] >> 4](dma_bytes);
|
|
|
|
/* Check if DMA is finished */
|
|
if (!dma_length)
|
|
{
|
|
/* DMA source address registers are incremented during DMA */
|
|
uint16 end = reg[21] + (reg[22] << 8) + reg[19] + (reg[20] << 8);
|
|
reg[21] = end & 0xff;
|
|
reg[22] = end >> 8;
|
|
|
|
/* DMA length registers are decremented during DMA */
|
|
reg[19] = reg[20] = 0;
|
|
|
|
/* perform cached write, if any */
|
|
if (cached_write >= 0)
|
|
{
|
|
vdp_68k_ctrl_w(cached_write);
|
|
cached_write = -1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* Control port access functions */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
void vdp_68k_ctrl_w(unsigned int data)
|
|
{
|
|
/* Check pending flag */
|
|
if (pending == 0)
|
|
{
|
|
/* A single long word write instruction could have started DMA with the first word */
|
|
if (dma_length)
|
|
{
|
|
/* 68k is frozen during 68k bus DMA */
|
|
/* Second word should be written after DMA completion */
|
|
/* See Formula One & Kawasaki Superbike Challenge */
|
|
if (dma_type < 2)
|
|
{
|
|
/* Latch second control word for later */
|
|
cached_write = data;
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Check CD0-CD1 bits */
|
|
if ((data & 0xC000) == 0x8000)
|
|
{
|
|
/* VDP register write */
|
|
vdp_reg_w((data >> 8) & 0x1F, data & 0xFF, m68k.cycles);
|
|
}
|
|
else
|
|
{
|
|
/* Set pending flag (Mode 5 only) */
|
|
pending = reg[1] & 4;
|
|
}
|
|
|
|
/* Update address and code registers */
|
|
addr = addr_latch | (data & 0x3FFF);
|
|
code = ((code & 0x3C) | ((data >> 14) & 0x03));
|
|
}
|
|
else
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Save address bits A15 and A14 */
|
|
addr_latch = (data & 3) << 14;
|
|
|
|
/* Update address and code registers */
|
|
addr = addr_latch | (addr & 0x3FFF);
|
|
code = ((code & 0x03) | ((data >> 2) & 0x3C));
|
|
|
|
/* Detect DMA operation (CD5 bit set) */
|
|
if (code & 0x20)
|
|
{
|
|
/* DMA must be enabled */
|
|
if (reg[1] & 0x10)
|
|
{
|
|
/* DMA type */
|
|
switch (reg[23] >> 6)
|
|
{
|
|
case 2:
|
|
{
|
|
/* DMA Fill will be triggered by next DATA port write */
|
|
dmafill = 0x100;
|
|
break;
|
|
}
|
|
|
|
case 3:
|
|
{
|
|
/* DMA length */
|
|
dma_length = (reg[20] << 8) | reg[19];
|
|
|
|
/* Zero DMA length */
|
|
if (!dma_length)
|
|
{
|
|
dma_length = 0x10000;
|
|
}
|
|
|
|
/* DMA source address */
|
|
dma_src = (reg[22] << 8) | reg[21];
|
|
|
|
/* trigger DMA copy */
|
|
dma_type = 3;
|
|
vdp_dma_update(m68k.cycles);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
/* DMA length */
|
|
dma_length = (reg[20] << 8) | reg[19];
|
|
|
|
/* Zero DMA length */
|
|
if (!dma_length)
|
|
{
|
|
dma_length = 0x10000;
|
|
}
|
|
|
|
/* DMA source address */
|
|
dma_src = (reg[22] << 8) | reg[21];
|
|
|
|
/* Transfer from SVP ROM/RAM ($000000-$3fffff) or CD Word-RAM ($200000-$3fffff/$600000-$7fffff) */
|
|
if (((system_hw == SYSTEM_MCD) && ((reg[23] & 0x70) == ((scd.cartridge.boot >> 1) + 0x10))) || (svp && !(reg[23] & 0x60)))
|
|
{
|
|
/* source data is available with one cycle delay, i.e first word written by VDP is */
|
|
/* previous data being held on 68k bus at that time, then source words are written */
|
|
/* normally to VDP RAM, with only last source word being ignored */
|
|
addr += reg[15];
|
|
dma_length--;
|
|
}
|
|
|
|
/* trigger DMA from 68k bus */
|
|
dma_type = (code & 0x06) ? 0 : 1;
|
|
vdp_dma_update(m68k.cycles);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
FIFO emulation (Chaos Engine/Soldier of Fortune, Double Clutch, Sol Deace)
|
|
--------------------------------------------------------------------------
|
|
|
|
CPU access per line is limited during active display:
|
|
H32: 16 access --> 3420/16 = ~214 Mcycles between access
|
|
H40: 18 access --> 3420/18 = ~190 Mcycles between access
|
|
|
|
This is an approximation: on real hardware, access slots are fixed.
|
|
|
|
Each VRAM access is byte wide, so one VRAM write (word) need twice cycles.
|
|
|
|
Note: Invalid code 0x02 (register write) apparently behaves the same as VRAM
|
|
access, although no data is written in this case (fixes Clue menu)
|
|
*/
|
|
fifo_latency = (reg[12] & 1) ? 190 : 214;
|
|
fifo_latency <<= ((code & 0x0F) < 0x03);
|
|
}
|
|
|
|
/* Mega Drive VDP control port specific (MS compatibility mode) */
|
|
void vdp_z80_ctrl_w(unsigned int data)
|
|
{
|
|
switch (pending)
|
|
{
|
|
case 0:
|
|
{
|
|
/* Latch LSB */
|
|
addr_latch = data;
|
|
|
|
/* Set LSB pending flag */
|
|
pending = 1;
|
|
return;
|
|
}
|
|
|
|
case 1:
|
|
{
|
|
/* Update address and code registers */
|
|
addr = (addr & 0xC000) | ((data & 0x3F) << 8) | addr_latch ;
|
|
code = ((code & 0x3C) | ((data >> 6) & 0x03));
|
|
|
|
if ((code & 0x03) == 0x02)
|
|
{
|
|
/* VDP register write */
|
|
vdp_reg_w(data & 0x1F, addr_latch, Z80.cycles);
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
return;
|
|
}
|
|
|
|
/* Set Mode 5 pending flag */
|
|
pending = (reg[1] & 4) >> 1;
|
|
|
|
if (!pending && !(code & 0x03))
|
|
{
|
|
/* Process VRAM read */
|
|
fifo[0] = vram[addr & 0x3FFF];
|
|
|
|
/* Increment address register */
|
|
addr += (reg[15] + 1);
|
|
}
|
|
return;
|
|
}
|
|
|
|
case 2:
|
|
{
|
|
/* Latch LSB */
|
|
addr_latch = data;
|
|
|
|
/* Set LSB pending flag */
|
|
pending = 3;
|
|
return;
|
|
}
|
|
|
|
case 3:
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Update address and code registers */
|
|
addr = ((addr_latch & 3) << 14) | (addr & 0x3FFF);
|
|
code = ((code & 0x03) | ((addr_latch >> 2) & 0x3C));
|
|
|
|
/* Detect DMA operation (CD5 bit set) */
|
|
if (code & 0x20)
|
|
{
|
|
/* DMA should be enabled */
|
|
if (reg[1] & 0x10)
|
|
{
|
|
/* DMA type */
|
|
switch (reg[23] >> 6)
|
|
{
|
|
case 2:
|
|
{
|
|
/* DMA Fill will be triggered by next write to DATA port */
|
|
dmafill = 0x100;
|
|
break;
|
|
}
|
|
|
|
case 3:
|
|
{
|
|
/* DMA length */
|
|
dma_length = (reg[20] << 8) | reg[19];
|
|
|
|
/* Zero DMA length */
|
|
if (!dma_length)
|
|
{
|
|
dma_length = 0x10000;
|
|
}
|
|
|
|
/* DMA source address */
|
|
dma_src = (reg[22] << 8) | reg[21];
|
|
|
|
/* trigger DMA copy */
|
|
dma_type = 3;
|
|
vdp_dma_update(Z80.cycles);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
/* DMA from 68k bus does not work when Z80 is in control */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Master System & Game Gear VDP control port specific */
|
|
void vdp_sms_ctrl_w(unsigned int data)
|
|
{
|
|
if(pending == 0)
|
|
{
|
|
/* Update address register LSB */
|
|
addr = (addr & 0x3F00) | (data & 0xFF);
|
|
|
|
/* Latch LSB */
|
|
addr_latch = data;
|
|
|
|
/* Set LSB pending flag */
|
|
pending = 1;
|
|
}
|
|
else
|
|
{
|
|
/* Update address and code registers */
|
|
code = (data >> 6) & 3;
|
|
addr = (data << 8 | addr_latch) & 0x3FFF;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
if (code == 0)
|
|
{
|
|
/* Process VRAM read */
|
|
fifo[0] = vram[addr & 0x3FFF];
|
|
|
|
/* Increment address register */
|
|
addr = (addr + 1) & 0x3FFF;
|
|
return;
|
|
}
|
|
|
|
if (code == 2)
|
|
{
|
|
/* Save current VDP mode */
|
|
int mode, prev = (reg[0] & 0x06) | (reg[1] & 0x18);
|
|
|
|
/* Write VDP register 0-15 */
|
|
vdp_reg_w(data & 0x0F, addr_latch, Z80.cycles);
|
|
|
|
/* Check VDP mode changes */
|
|
mode = (reg[0] & 0x06) | (reg[1] & 0x18);
|
|
prev ^= mode;
|
|
|
|
if (prev)
|
|
{
|
|
/* Check for extended modes */
|
|
if (system_hw > SYSTEM_SMS)
|
|
{
|
|
int height;
|
|
|
|
if (mode == 0x0E) /* M1=0,M2=1,M3=1,M4=1 */
|
|
{
|
|
/* Mode 4 extended (240 lines) */
|
|
height = 240;
|
|
|
|
/* Update vertical counter max value */
|
|
vc_max = vc_table[3][vdp_pal];
|
|
}
|
|
else if (mode == 0x16) /* M1=1,M2=1,M3=0,M4=1 */
|
|
{
|
|
/* Mode 4 extended (224 lines) */
|
|
height = 224;
|
|
|
|
/* Update vertical counter max value */
|
|
vc_max = vc_table[1][vdp_pal];
|
|
}
|
|
else
|
|
{
|
|
/* Mode 4 default (224 lines) */
|
|
height = 192;
|
|
|
|
/* Default vertical counter max value */
|
|
vc_max = vc_table[0][vdp_pal];
|
|
}
|
|
|
|
if (height != bitmap.viewport.h)
|
|
{
|
|
if (status & 8)
|
|
{
|
|
/* viewport changes should be applied on next frame */
|
|
bitmap.viewport.changed |= 2;
|
|
}
|
|
else
|
|
{
|
|
/* update active display */
|
|
bitmap.viewport.h = height;
|
|
|
|
/* update vertical overscan */
|
|
if (config.overscan & 1)
|
|
{
|
|
bitmap.viewport.y = (240 + 48*vdp_pal - height) >> 1;
|
|
}
|
|
else
|
|
{
|
|
if ((system_hw == SYSTEM_GG) && !config.gg_extra)
|
|
{
|
|
/* Display area reduced to 160x144 */
|
|
bitmap.viewport.y = (144 - height) / 2;
|
|
}
|
|
else
|
|
{
|
|
bitmap.viewport.y = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Rendering mode */
|
|
switch (mode)
|
|
{
|
|
case 0x00: /* Graphics I */
|
|
{
|
|
render_bg = render_bg_m0;
|
|
break;
|
|
}
|
|
|
|
case 0x10: /* Text */
|
|
{
|
|
render_bg = render_bg_m1;
|
|
break;
|
|
}
|
|
|
|
case 0x02: /* Graphics II */
|
|
{
|
|
render_bg = render_bg_m2;
|
|
break;
|
|
}
|
|
|
|
case 0x12: /* Text (Extended PG) */
|
|
{
|
|
render_bg = render_bg_m1x;
|
|
break;
|
|
}
|
|
|
|
case 0x08: /* Multicolor */
|
|
{
|
|
render_bg = render_bg_m3;
|
|
break;
|
|
}
|
|
|
|
case 0x18: /* Invalid (1+3) */
|
|
{
|
|
render_bg = render_bg_inv;
|
|
break;
|
|
}
|
|
|
|
case 0x0A: /* Multicolor (Extended PG) */
|
|
{
|
|
render_bg = render_bg_m3x;
|
|
break;
|
|
}
|
|
|
|
case 0x1A: /* Invalid (1+2+3) */
|
|
{
|
|
render_bg = render_bg_inv;
|
|
break;
|
|
}
|
|
|
|
default: /* Mode 4 */
|
|
{
|
|
render_bg = render_bg_m4;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Mode switching */
|
|
if (prev & 0x04)
|
|
{
|
|
int i;
|
|
|
|
if (mode & 0x04)
|
|
{
|
|
/* Mode 4 sprites */
|
|
parse_satb = parse_satb_m4;
|
|
render_obj = render_obj_m4;
|
|
|
|
/* force BG cache update*/
|
|
bg_list_index = 0x200;
|
|
}
|
|
else
|
|
{
|
|
/* TMS-mode sprites */
|
|
parse_satb = parse_satb_tms;
|
|
render_obj = render_obj_tms;
|
|
|
|
/* BG cache is not used */
|
|
bg_list_index = 0;
|
|
}
|
|
|
|
/* reinitialize palette */
|
|
for(i = 0; i < 0x20; i ++)
|
|
{
|
|
color_update_m4(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
color_update_m4(0x40, *(uint16 *)&cram[(0x10 | (border & 0x0F)) << 1]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* TMS9918 (SG-1000) VDP control port specific */
|
|
void vdp_tms_ctrl_w(unsigned int data)
|
|
{
|
|
if(pending == 0)
|
|
{
|
|
/* Latch LSB */
|
|
addr_latch = data;
|
|
|
|
/* Set LSB pending flag */
|
|
pending = 1;
|
|
}
|
|
else
|
|
{
|
|
/* Update address and code registers */
|
|
code = (data >> 6) & 3;
|
|
addr = (data << 8 | addr_latch) & 0x3FFF;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
if (code == 0)
|
|
{
|
|
/* Process VRAM read */
|
|
fifo[0] = vram[addr & 0x3FFF];
|
|
|
|
/* Increment address register */
|
|
addr = (addr + 1) & 0x3FFF;
|
|
return;
|
|
}
|
|
|
|
if (code & 2)
|
|
{
|
|
/* VDP register index (0-7) */
|
|
data &= 0x07;
|
|
|
|
/* Write VDP register */
|
|
vdp_reg_w(data, addr_latch, Z80.cycles);
|
|
|
|
/* Check VDP mode changes */
|
|
if (data < 2)
|
|
{
|
|
int mode = (reg[0] & 0x02) | (reg[1] & 0x18);
|
|
|
|
/* Rendering mode */
|
|
switch (mode)
|
|
{
|
|
case 0x00: /* Graphics I */
|
|
{
|
|
render_bg = render_bg_m0;
|
|
break;
|
|
}
|
|
|
|
case 0x10: /* Text */
|
|
{
|
|
render_bg = render_bg_m1;
|
|
break;
|
|
}
|
|
|
|
case 0x02: /* Graphics II */
|
|
{
|
|
render_bg = render_bg_m2;
|
|
break;
|
|
}
|
|
|
|
case 0x12: /* Text (Extended PG) */
|
|
{
|
|
render_bg = render_bg_m1x;
|
|
break;
|
|
}
|
|
|
|
case 0x08: /* Multicolor */
|
|
{
|
|
render_bg = render_bg_m3;
|
|
break;
|
|
}
|
|
|
|
case 0x18: /* Invalid (1+3) */
|
|
{
|
|
render_bg = render_bg_inv;
|
|
break;
|
|
}
|
|
|
|
case 0x0A: /* Multicolor (Extended PG) */
|
|
{
|
|
render_bg = render_bg_m3x;
|
|
break;
|
|
}
|
|
|
|
case 0x1A: /* Invalid (1+2+3) */
|
|
{
|
|
render_bg = render_bg_inv;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Status register
|
|
*
|
|
* Bits
|
|
* 0 NTSC(0)/PAL(1)
|
|
* 1 DMA Busy
|
|
* 2 During HBlank
|
|
* 3 During VBlank
|
|
* 4 0:1 even:odd field (interlaced modes only)
|
|
* 5 Sprite collision
|
|
* 6 Too many sprites per line
|
|
* 7 v interrupt occurred
|
|
* 8 Write FIFO full
|
|
* 9 Write FIFO empty
|
|
* 10 - 15 Open Bus
|
|
*/
|
|
unsigned int vdp_68k_ctrl_r(unsigned int cycles)
|
|
{
|
|
unsigned int temp;
|
|
|
|
/* Update FIFO flags */
|
|
vdp_fifo_update(cycles);
|
|
|
|
/* Update DMA Busy flag */
|
|
if ((status & 2) && !dma_length && (cycles >= dma_endCycles))
|
|
{
|
|
status &= 0xFFFD;
|
|
}
|
|
|
|
/* Return VDP status */
|
|
temp = status;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Clear SOVR & SCOL flags */
|
|
status &= 0xFF9F;
|
|
|
|
/* Display OFF: VBLANK flag is set */
|
|
if (!(reg[1] & 0x40))
|
|
{
|
|
temp |= 0x08;
|
|
}
|
|
|
|
/* HBLANK flag (Sonic 3 and Sonic 2 "VS Modes", Lemmings 2, Mega Turrican, V.R Troopers, Gouketsuji Ichizoku,...) */
|
|
/* NB: this is not 100% accurate and need to be verified on real hardware */
|
|
if ((cycles % MCYCLES_PER_LINE) < 588)
|
|
{
|
|
temp |= 0x04;
|
|
}
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VDP 68k status read -> 0x%x (0x%x) (%x)\n", v_counter, cycles/MCYCLES_PER_LINE-1, cycles, cycles%MCYCLES_PER_LINE, temp, status, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
return (temp);
|
|
}
|
|
|
|
unsigned int vdp_z80_ctrl_r(unsigned int cycles)
|
|
{
|
|
unsigned int temp;
|
|
|
|
/* Cycle-accurate SOVR & VINT flags */
|
|
int line = (lines_per_frame + (cycles / MCYCLES_PER_LINE) - 1) % lines_per_frame;
|
|
|
|
/* Update DMA Busy flag (Mega Drive VDP specific) */
|
|
if ((system_hw & SYSTEM_MD) && (status & 2) && !dma_length && (cycles >= dma_endCycles))
|
|
{
|
|
status &= 0xFD;
|
|
}
|
|
|
|
/* Check if we are already on next line */
|
|
if (line > v_counter)
|
|
{
|
|
v_counter = line;
|
|
if (line == (bitmap.viewport.h + 1))
|
|
{
|
|
/* set VINT flag (immediately cleared after) */
|
|
status |= 0x80;
|
|
}
|
|
else if ((line >= 0) && (line < bitmap.viewport.h) && !(work_ram[0x1ffb] & cart.special))
|
|
{
|
|
/* Check sprites overflow & collision */
|
|
render_line(line);
|
|
}
|
|
}
|
|
|
|
/* Return VDP status */
|
|
temp = status;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Clear VINT, SOVR & SCOL flags */
|
|
status &= 0xFF1F;
|
|
|
|
/* Mega Drive VDP specific */
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
/* Display OFF: VBLANK flag is set */
|
|
if (!(reg[1] & 0x40))
|
|
{
|
|
temp |= 0x08;
|
|
}
|
|
|
|
/* HBLANK flag */
|
|
if ((cycles % MCYCLES_PER_LINE) < 588)
|
|
{
|
|
temp |= 0x04;
|
|
}
|
|
}
|
|
else if (reg[0] & 0x04)
|
|
{
|
|
/* Mode 4 unused bits (fixes PGA Tour Golf) */
|
|
temp |= 0x1F;
|
|
}
|
|
|
|
/* Cycle-accurate SCOL flag */
|
|
if ((temp & 0x20) && (line == (spr_col >> 8)))
|
|
{
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
/* COL flag is set at HCount 0xFF on MD */
|
|
if ((cycles % MCYCLES_PER_LINE) < 105)
|
|
{
|
|
status |= 0x20;
|
|
temp &= ~0x20;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* COL flag is set at the pixel it occurs */
|
|
uint8 hc = hctab[(cycles + SMS_CYCLE_OFFSET + 15) % MCYCLES_PER_LINE];
|
|
if ((hc < (spr_col & 0xff)) || (hc > 0xf3))
|
|
{
|
|
status |= 0x20;
|
|
temp &= ~0x20;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Clear HINT & VINT pending flags */
|
|
hint_pending = vint_pending = 0;
|
|
|
|
/* Clear Z80 interrupt */
|
|
Z80.irq_state = CLEAR_LINE;
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VDP Z80 status read -> 0x%x (0x%x) (%x)\n", v_counter, cycles/MCYCLES_PER_LINE-1, cycles, cycles%MCYCLES_PER_LINE, temp, status, Z80.pc.w.l);
|
|
#endif
|
|
return (temp);
|
|
}
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* HV Counters */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
unsigned int vdp_hvc_r(unsigned int cycles)
|
|
{
|
|
int vc;
|
|
unsigned int data = hvc_latch;
|
|
|
|
/* Check if HVC latch is enabled */
|
|
if (data)
|
|
{
|
|
/* Mode 5: HV-counters are frozen (cf. lightgun games, Sunset Riders logo) */
|
|
if (reg[1] & 0x04)
|
|
{
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] HVC latch read -> 0x%x (%x)\n", v_counter, (cycles/MCYCLES_PER_LINE-1)%lines_per_frame, cycles, cycles%MCYCLES_PER_LINE, data & 0xffff, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
/* return latched HVC value */
|
|
return (data & 0xffff);
|
|
}
|
|
else
|
|
{
|
|
/* Mode 4: by default, V-counter runs normally & H counter is frozen */
|
|
data &= 0xff;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Cycle-accurate H-Counter (Striker, Mickey Mania, Skitchin, Road Rash I,II,III, Sonic 3D Blast...) */
|
|
data = hctab[cycles % MCYCLES_PER_LINE];
|
|
}
|
|
|
|
/* Cycle-accurate V-Counter (cycle counter starts from line -1) */
|
|
vc = (cycles / MCYCLES_PER_LINE) - 1;
|
|
|
|
/* V-Counter overflow */
|
|
if (vc > vc_max)
|
|
{
|
|
vc -= lines_per_frame;
|
|
}
|
|
|
|
/* Interlaced modes */
|
|
if (interlaced)
|
|
{
|
|
/* Interlace mode 2 (Sonic the Hedgehog 2, Combat Cars) */
|
|
vc <<= im2_flag;
|
|
|
|
/* Replace bit 0 with bit 8 */
|
|
vc = (vc & ~1) | ((vc >> 8) & 1);
|
|
}
|
|
|
|
/* return H-Counter in LSB & V-Counter in MSB */
|
|
data |= ((vc & 0xff) << 8);
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] HVC read -> 0x%x (%x)\n", v_counter, (cycles/MCYCLES_PER_LINE-1)%lines_per_frame, cycles, cycles%MCYCLES_PER_LINE, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
return (data);
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* Test registers */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
void vdp_test_w(unsigned int data)
|
|
{
|
|
#ifdef LOGERROR
|
|
error("Unused VDP Write 0x%x (%08x)\n", data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* 68k interrupt handler (TODO: check how interrupts are handled in Mode 4) */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
int vdp_68k_irq_ack(int int_level)
|
|
{
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] INT Level %d ack (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE,int_level, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
|
|
/* VINT has higher priority (Fatal Rewind) */
|
|
if (vint_pending & reg[1])
|
|
{
|
|
#ifdef LOGVDP
|
|
error("---> VINT cleared\n");
|
|
#endif
|
|
|
|
/* Clear VINT pending flag */
|
|
vint_pending = 0;
|
|
status &= ~0x80;
|
|
|
|
/* Update IRQ status */
|
|
if (hint_pending & reg[0])
|
|
{
|
|
m68k_set_irq(4);
|
|
}
|
|
else
|
|
{
|
|
m68k_set_irq(0);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
#ifdef LOGVDP
|
|
error("---> HINT cleared\n");
|
|
#endif
|
|
|
|
/* Clear HINT pending flag */
|
|
hint_pending = 0;
|
|
|
|
/* Update IRQ status */
|
|
m68k_set_irq(0);
|
|
}
|
|
|
|
return M68K_INT_ACK_AUTOVECTOR;
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* VDP registers update function */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
static void vdp_reg_w(unsigned int r, unsigned int d, unsigned int cycles)
|
|
{
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VDP register %d write -> 0x%x (%x)\n", v_counter, cycles/MCYCLES_PER_LINE-1, cycles, cycles%MCYCLES_PER_LINE, r, d, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
|
|
/* VDP registers #11 to #23 cannot be updated in Mode 4 (Captain Planet & Avengers, Bass Master Classic Pro Edition) */
|
|
if (!(reg[1] & 4) && (r > 10))
|
|
{
|
|
return;
|
|
}
|
|
|
|
switch(r)
|
|
{
|
|
case 0: /* CTRL #1 */
|
|
{
|
|
/* Look for changed bits */
|
|
r = d ^ reg[0];
|
|
reg[0] = d;
|
|
|
|
/* Line Interrupt */
|
|
if ((r & 0x10) && hint_pending)
|
|
{
|
|
/* Update IRQ status */
|
|
if (vint_pending & reg[1])
|
|
{
|
|
set_irq_line(6);
|
|
}
|
|
else if (d & 0x10)
|
|
{
|
|
set_irq_line_delay(4);
|
|
}
|
|
else
|
|
{
|
|
set_irq_line(0);
|
|
}
|
|
}
|
|
|
|
/* Palette selection */
|
|
if (r & 0x04)
|
|
{
|
|
/* Mega Drive VDP only */
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
/* Reset color palette */
|
|
int i;
|
|
if (reg[1] & 0x04)
|
|
{
|
|
/* Mode 5 */
|
|
color_update_m5(0x00, *(uint16 *)&cram[border << 1]);
|
|
for (i = 1; i < 0x40; i++)
|
|
{
|
|
color_update_m5(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Mode 4 */
|
|
for (i = 0; i < 0x20; i++)
|
|
{
|
|
color_update_m4(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
color_update_m4(0x40, *(uint16 *)&cram[(0x10 | (border & 0x0F)) << 1]);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* HVC latch (Sunset Riders, Lightgun games) */
|
|
if (r & 0x02)
|
|
{
|
|
/* Mega Drive VDP only */
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
/* Mode 5 only */
|
|
if (reg[1] & 0x04)
|
|
{
|
|
if (d & 0x02)
|
|
{
|
|
/* Latch current HVC */
|
|
hvc_latch = vdp_hvc_r(cycles) | 0x10000;
|
|
}
|
|
else
|
|
{
|
|
/* Free-running HVC */
|
|
hvc_latch = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 1: /* CTRL #2 */
|
|
{
|
|
/* Look for changed bits */
|
|
r = d ^ reg[1];
|
|
reg[1] = d;
|
|
|
|
/* Display status (modified during active display) */
|
|
if ((r & 0x40) && (v_counter < bitmap.viewport.h))
|
|
{
|
|
/* Cycle offset vs HBLANK */
|
|
int offset = cycles - mcycles_vdp - 860;
|
|
if (offset <= 0)
|
|
{
|
|
/* If display was disabled during HBLANK (Mickey Mania 3D level), sprite rendering is limited */
|
|
if ((d & 0x40) && (object_count > 5) && (offset >= -500))
|
|
{
|
|
object_count = 5;
|
|
}
|
|
|
|
/* Redraw entire line (Legend of Galahad, Lemmings 2, Formula One, Kawasaki Super Bike, Deadly Moves,...) */
|
|
render_line(v_counter);
|
|
|
|
#ifdef LOGVDP
|
|
error("Line redrawn (%d sprites) \n",object_count);
|
|
#endif
|
|
}
|
|
else if (system_hw & SYSTEM_MD)
|
|
{
|
|
/* Active pixel offset */
|
|
if (reg[12] & 1)
|
|
{
|
|
/* dot clock = MCLK / 8 */
|
|
offset = (offset / 8);
|
|
}
|
|
else
|
|
{
|
|
/* dot clock = MCLK / 10 */
|
|
offset = (offset / 10) + 16;
|
|
}
|
|
|
|
/* Line is partially blanked (Nigel Mansell's World Championship Racing , Ren & Stimpy Show, ...) */
|
|
if (offset < bitmap.viewport.w)
|
|
{
|
|
#ifdef LOGVDP
|
|
error("Line %d redrawn from pixel %d\n",v_counter,offset);
|
|
#endif
|
|
if (d & 0x40)
|
|
{
|
|
render_line(v_counter);
|
|
blank_line(v_counter, 0, offset);
|
|
}
|
|
else
|
|
{
|
|
blank_line(v_counter, offset, bitmap.viewport.w - offset);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Frame Interrupt */
|
|
if ((r & 0x20) && vint_pending)
|
|
{
|
|
/* Update IRQ status */
|
|
if (d & 0x20)
|
|
{
|
|
set_irq_line_delay(6);
|
|
}
|
|
else if (hint_pending & reg[0])
|
|
{
|
|
set_irq_line(4);
|
|
}
|
|
else
|
|
{
|
|
set_irq_line(0);
|
|
}
|
|
}
|
|
|
|
/* Active display height */
|
|
if (r & 0x08)
|
|
{
|
|
/* Mega Drive VDP only */
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
/* Mode 5 only */
|
|
if (d & 0x04)
|
|
{
|
|
if (status & 8)
|
|
{
|
|
/* Changes should be applied on next frame */
|
|
bitmap.viewport.changed |= 2;
|
|
}
|
|
else
|
|
{
|
|
/* Update active display height */
|
|
bitmap.viewport.h = 224 + ((d & 8) << 1);
|
|
bitmap.viewport.y = (config.overscan & 1) * (8 - (d & 8) + 24*vdp_pal);
|
|
}
|
|
|
|
/* Update vertical counter max value */
|
|
vc_max = vc_table[(d >> 2) & 3][vdp_pal];
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Rendering mode */
|
|
if (r & 0x04)
|
|
{
|
|
/* Mega Drive VDP only */
|
|
if (system_hw & SYSTEM_MD)
|
|
{
|
|
int i;
|
|
if (d & 0x04)
|
|
{
|
|
/* Mode 5 rendering */
|
|
parse_satb = parse_satb_m5;
|
|
update_bg_pattern_cache = update_bg_pattern_cache_m5;
|
|
if (im2_flag)
|
|
{
|
|
render_bg = (reg[11] & 0x04) ? render_bg_m5_im2_vs : render_bg_m5_im2;
|
|
render_obj = (reg[12] & 0x08) ? render_obj_m5_im2_ste : render_obj_m5_im2;
|
|
}
|
|
else
|
|
{
|
|
render_bg = (reg[11] & 0x04) ? render_bg_m5_vs : render_bg_m5;
|
|
render_obj = (reg[12] & 0x08) ? render_obj_m5_ste : render_obj_m5;
|
|
}
|
|
|
|
/* Reset color palette */
|
|
color_update_m5(0x00, *(uint16 *)&cram[border << 1]);
|
|
for (i = 1; i < 0x40; i++)
|
|
{
|
|
color_update_m5(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
|
|
/* Mode 5 bus access */
|
|
vdp_68k_data_w = vdp_68k_data_w_m5;
|
|
vdp_z80_data_w = vdp_z80_data_w_m5;
|
|
vdp_68k_data_r = vdp_68k_data_r_m5;
|
|
vdp_z80_data_r = vdp_z80_data_r_m5;
|
|
|
|
/* Change display height */
|
|
if (status & 8)
|
|
{
|
|
/* viewport changes should be applied on next frame */
|
|
bitmap.viewport.changed |= 2;
|
|
}
|
|
else
|
|
{
|
|
/* Update current frame active display height */
|
|
bitmap.viewport.h = 224 + ((d & 8) << 1);
|
|
bitmap.viewport.y = (config.overscan & 1) * (8 - (d & 8) + 24*vdp_pal);
|
|
}
|
|
|
|
/* Clear HVC latched value */
|
|
hvc_latch = 0;
|
|
|
|
/* Check if HVC latch bit is set */
|
|
if (reg[0] & 0x02)
|
|
{
|
|
/* Latch current HVC */
|
|
hvc_latch = vdp_hvc_r(cycles) | 0x10000;
|
|
}
|
|
|
|
/* max tiles to invalidate */
|
|
bg_list_index = 0x800;
|
|
}
|
|
else
|
|
{
|
|
/* Mode 4 rendering */
|
|
parse_satb = parse_satb_m4;
|
|
update_bg_pattern_cache = update_bg_pattern_cache_m4;
|
|
render_bg = render_bg_m4;
|
|
render_obj = render_obj_m4;
|
|
|
|
/* Reset color palette */
|
|
for (i = 0; i < 0x20; i++)
|
|
{
|
|
color_update_m4(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
color_update_m4(0x40, *(uint16 *)&cram[(0x10 | (border & 0x0F)) << 1]);
|
|
|
|
/* Mode 4 bus access */
|
|
vdp_68k_data_w = vdp_68k_data_w_m4;
|
|
vdp_z80_data_w = vdp_z80_data_w_m4;
|
|
vdp_68k_data_r = vdp_68k_data_r_m4;
|
|
vdp_z80_data_r = vdp_z80_data_r_m4;
|
|
|
|
if (status & 8)
|
|
{
|
|
/* viewport changes should be applied on next frame */
|
|
bitmap.viewport.changed |= 2;
|
|
}
|
|
else
|
|
{
|
|
/* Update current frame active display */
|
|
bitmap.viewport.h = 192;
|
|
bitmap.viewport.y = (config.overscan & 1) * 24 * (vdp_pal + 1);
|
|
}
|
|
|
|
/* Latch current HVC */
|
|
hvc_latch = vdp_hvc_r(cycles) | 0x10000;
|
|
|
|
/* max tiles to invalidate */
|
|
bg_list_index = 0x200;
|
|
}
|
|
|
|
/* Invalidate pattern cache */
|
|
for (i=0;i<bg_list_index;i++)
|
|
{
|
|
bg_name_list[i] = i;
|
|
bg_name_dirty[i] = 0xFF;
|
|
}
|
|
|
|
/* Update vertical counter max value */
|
|
vc_max = vc_table[(d >> 2) & 3][vdp_pal];
|
|
}
|
|
else
|
|
{
|
|
/* No effect (cleared to avoid mode 5 detection elsewhere) */
|
|
reg[1] &= ~0x04;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 2: /* Plane A Name Table Base */
|
|
{
|
|
reg[2] = d;
|
|
ntab = (d << 10) & 0xE000;
|
|
|
|
/* Plane A Name Table Base changed during HBLANK */
|
|
if ((v_counter < bitmap.viewport.h) && (reg[1] & 0x40) && (cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* render entire line */
|
|
render_line(v_counter);
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 3: /* Window Plane Name Table Base */
|
|
{
|
|
reg[3] = d;
|
|
if (reg[12] & 0x01)
|
|
{
|
|
ntwb = (d << 10) & 0xF000;
|
|
}
|
|
else
|
|
{
|
|
ntwb = (d << 10) & 0xF800;
|
|
}
|
|
|
|
/* Window Plane Name Table Base changed during HBLANK */
|
|
if ((v_counter < bitmap.viewport.h) && (reg[1] & 0x40) && (cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* render entire line */
|
|
render_line(v_counter);
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 4: /* Plane B Name Table Base */
|
|
{
|
|
reg[4] = d;
|
|
ntbb = (d << 13) & 0xE000;
|
|
|
|
/* Plane B Name Table Base changed during HBLANK (Adventures of Batman & Robin) */
|
|
if ((v_counter < bitmap.viewport.h) && (reg[1] & 0x40) && (cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* render entire line */
|
|
render_line(v_counter);
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
case 5: /* Sprite Attribute Table Base */
|
|
{
|
|
reg[5] = d;
|
|
satb = (d << 9) & sat_base_mask;
|
|
break;
|
|
}
|
|
|
|
case 7: /* Backdrop color */
|
|
{
|
|
reg[7] = d;
|
|
|
|
/* Check if backdrop color changed */
|
|
d &= 0x3F;
|
|
|
|
if (d != border)
|
|
{
|
|
/* Update backdrop color */
|
|
border = d;
|
|
|
|
/* Reset palette entry */
|
|
if (reg[1] & 4)
|
|
{
|
|
/* Mode 5 */
|
|
color_update_m5(0x00, *(uint16 *)&cram[d << 1]);
|
|
}
|
|
else
|
|
{
|
|
/* Mode 4 */
|
|
color_update_m4(0x40, *(uint16 *)&cram[(0x10 | (d & 0x0F)) << 1]);
|
|
}
|
|
|
|
/* Backdrop color modified during HBLANK (Road Rash 1,2,3)*/
|
|
if ((v_counter < bitmap.viewport.h) && (cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* remap entire line */
|
|
remap_line(v_counter);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 8: /* Horizontal Scroll (Mode 4 only) */
|
|
{
|
|
int line;
|
|
|
|
/* Hscroll is latched at HCount 0xF3, HCount 0xF6 on MD */
|
|
/* Line starts at HCount 0xF4, HCount 0xF6 on MD */
|
|
if (system_hw < SYSTEM_MD)
|
|
{
|
|
cycles = cycles + 15;
|
|
}
|
|
|
|
/* Make sure Hscroll has not already been latched */
|
|
line = (lines_per_frame + (cycles / MCYCLES_PER_LINE) - 1) % lines_per_frame;
|
|
if ((line > v_counter) && (line < bitmap.viewport.h) && !(work_ram[0x1ffb] & cart.special))
|
|
{
|
|
v_counter = line;
|
|
render_line(line);
|
|
}
|
|
|
|
reg[8] = d;
|
|
break;
|
|
}
|
|
|
|
case 11: /* CTRL #3 */
|
|
{
|
|
reg[11] = d;
|
|
|
|
/* Horizontal scrolling mode */
|
|
hscroll_mask = hscroll_mask_table[d & 0x03];
|
|
|
|
/* Vertical Scrolling mode */
|
|
if (d & 0x04)
|
|
{
|
|
render_bg = im2_flag ? render_bg_m5_im2_vs : render_bg_m5_vs;
|
|
}
|
|
else
|
|
{
|
|
render_bg = im2_flag ? render_bg_m5_im2 : render_bg_m5;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 12: /* CTRL #4 */
|
|
{
|
|
/* Look for changed bits */
|
|
r = d ^ reg[12];
|
|
reg[12] = d;
|
|
|
|
/* Shadow & Highlight mode */
|
|
if (r & 0x08)
|
|
{
|
|
/* Reset color palette */
|
|
int i;
|
|
color_update_m5(0x00, *(uint16 *)&cram[border << 1]);
|
|
for (i = 1; i < 0x40; i++)
|
|
{
|
|
color_update_m5(i, *(uint16 *)&cram[i << 1]);
|
|
}
|
|
|
|
/* Update sprite rendering function */
|
|
if (d & 0x08)
|
|
{
|
|
render_obj = im2_flag ? render_obj_m5_im2_ste : render_obj_m5_ste;
|
|
}
|
|
else
|
|
{
|
|
render_obj = im2_flag ? render_obj_m5_im2 : render_obj_m5;
|
|
}
|
|
}
|
|
|
|
/* Interlaced modes */
|
|
if (r & 0x06)
|
|
{
|
|
/* changes should be applied on next frame */
|
|
bitmap.viewport.changed |= 2;
|
|
}
|
|
|
|
/* Active display width */
|
|
if (r & 0x01)
|
|
{
|
|
if (d & 0x01)
|
|
{
|
|
/* Update display-dependant registers */
|
|
ntwb = (reg[3] << 10) & 0xF000;
|
|
satb = (reg[5] << 9) & 0xFC00;
|
|
sat_base_mask = 0xFC00;
|
|
sat_addr_mask = 0x03FF;
|
|
|
|
/* Update HC table */
|
|
hctab = cycle2hc40;
|
|
|
|
/* Update clipping */
|
|
window_clip(reg[17], 1);
|
|
|
|
/* Update fifo timings */
|
|
fifo_latency = 190;
|
|
}
|
|
else
|
|
{
|
|
/* Update display-dependant registers */
|
|
ntwb = (reg[3] << 10) & 0xF800;
|
|
satb = (reg[5] << 9) & 0xFE00;
|
|
sat_base_mask = 0xFE00;
|
|
sat_addr_mask = 0x01FF;
|
|
|
|
/* Update HC table */
|
|
hctab = cycle2hc32;
|
|
|
|
/* Update clipping */
|
|
window_clip(reg[17], 0);
|
|
|
|
/* Update FIFO timings */
|
|
fifo_latency = 214;
|
|
}
|
|
|
|
/* Adjust FIFO timings for VRAM writes */
|
|
fifo_latency <<= ((code & 0x0F) < 0x03);
|
|
|
|
/* Active display width modified during HBLANK (Bugs Bunny Double Trouble) */
|
|
if ((v_counter < bitmap.viewport.h) && (cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* Update active display width */
|
|
bitmap.viewport.w = 256 + ((d & 1) << 6);
|
|
|
|
/* Redraw entire line */
|
|
render_line(v_counter);
|
|
}
|
|
else if (v_counter == (lines_per_frame - 1))
|
|
{
|
|
/* Update starting frame active display width */
|
|
bitmap.viewport.w = 256 + ((d & 1) << 6);
|
|
}
|
|
else
|
|
{
|
|
/* Changes should be applied on next frame (Golden Axe III intro) */
|
|
/* NB: not 100% accurate but required since backend framebuffer width cannot be modified mid-frame. */
|
|
/* This would require a fixed framebuffer width (based on TV screen aspect ratio) and pixel scaling */
|
|
/* to be done during rendering (depending on active display pixel aspect ratio in H32 or H40 mode). */
|
|
/* Display is generally disabled when this is modified so it shouldn't be really noticeable anyway. */
|
|
bitmap.viewport.changed |= 2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 13: /* HScroll Base Address */
|
|
{
|
|
reg[13] = d;
|
|
hscb = (d << 10) & 0xFC00;
|
|
break;
|
|
}
|
|
|
|
case 16: /* Playfield size */
|
|
{
|
|
reg[16] = d;
|
|
playfield_shift = shift_table[(d & 3)];
|
|
playfield_col_mask = col_mask_table[(d & 3)];
|
|
playfield_row_mask = row_mask_table[(d >> 4) & 3];
|
|
break;
|
|
}
|
|
|
|
case 17: /* Window/Plane A vertical clipping */
|
|
{
|
|
reg[17] = d;
|
|
window_clip(d, reg[12] & 1);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
reg[r] = d;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* FIFO update function (Genesis mode only) */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
static void vdp_fifo_update(unsigned int cycles)
|
|
{
|
|
if (fifo_write_cnt > 0)
|
|
{
|
|
/* Get number of FIFO reads */
|
|
int fifo_read = ((cycles - fifo_lastwrite) / fifo_latency);
|
|
|
|
if (fifo_read > 0)
|
|
{
|
|
/* Process FIFO entries */
|
|
fifo_write_cnt -= fifo_read;
|
|
|
|
/* Clear FIFO full flag */
|
|
status &= 0xFEFF;
|
|
|
|
/* Check remaining FIFO entries */
|
|
if (fifo_write_cnt <= 0)
|
|
{
|
|
/* Set FIFO empty flag */
|
|
status |= 0x200;
|
|
fifo_write_cnt = 0;
|
|
}
|
|
|
|
/* Update FIFO cycle count */
|
|
fifo_lastwrite += (fifo_read * fifo_latency);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* Internal 16-bit data bus access function (Mode 5 only) */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
static void vdp_bus_w(unsigned int data)
|
|
{
|
|
/* Check destination code */
|
|
switch (code & 0x0F)
|
|
{
|
|
case 0x01: /* VRAM */
|
|
{
|
|
/* VRAM address */
|
|
int index = addr & 0xFFFE;
|
|
|
|
/* Pointer to VRAM */
|
|
uint16 *p = (uint16 *)&vram[index];
|
|
|
|
/* Byte-swap data if A0 is set */
|
|
if (addr & 1)
|
|
{
|
|
data = ((data >> 8) | (data << 8)) & 0xFFFF;
|
|
}
|
|
|
|
/* Intercept writes to Sprite Attribute Table */
|
|
if ((index & sat_base_mask) == satb)
|
|
{
|
|
/* Update internal SAT */
|
|
*(uint16 *) &sat[index & sat_addr_mask] = data;
|
|
}
|
|
|
|
/* Only write unique data to VRAM */
|
|
if (data != *p)
|
|
{
|
|
int name;
|
|
|
|
/* Write data to VRAM */
|
|
*p = data;
|
|
|
|
/* Update pattern cache */
|
|
MARK_BG_DIRTY (index);
|
|
}
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VRAM 0x%x write -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
case 0x03: /* CRAM */
|
|
{
|
|
/* Pointer to CRAM 9-bit word */
|
|
uint16 *p = (uint16 *)&cram[addr & 0x7E];
|
|
|
|
/* Pack 16-bit bus data (BBB0GGG0RRR0) to 9-bit CRAM data (BBBGGGRRR) */
|
|
data = ((data & 0xE00) >> 3) | ((data & 0x0E0) >> 2) | ((data & 0x00E) >> 1);
|
|
|
|
/* Check if CRAM data is being modified */
|
|
if (data != *p)
|
|
{
|
|
/* CRAM index (64 words) */
|
|
int index = (addr >> 1) & 0x3F;
|
|
|
|
/* Write CRAM data */
|
|
*p = data;
|
|
|
|
/* Color entry 0 of each palette is never displayed (transparent pixel) */
|
|
if (index & 0x0F)
|
|
{
|
|
/* Update color palette */
|
|
color_update_m5(index, data);
|
|
}
|
|
|
|
/* Update backdrop color */
|
|
if (index == border)
|
|
{
|
|
color_update_m5(0x00, data);
|
|
}
|
|
|
|
/* CRAM modified during HBLANK (Striker, Zero the Kamikaze, etc) */
|
|
if ((v_counter < bitmap.viewport.h) && (reg[1]& 0x40) && (m68k.cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* Remap current line */
|
|
remap_line(v_counter);
|
|
}
|
|
}
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] CRAM 0x%x write -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
case 0x05: /* VSRAM */
|
|
{
|
|
*(uint16 *)&vsram[addr & 0x7E] = data;
|
|
|
|
/* 2-cell Vscroll mode */
|
|
if (reg[11] & 0x04)
|
|
{
|
|
/* VSRAM writes during HBLANK (Adventures of Batman & Robin) */
|
|
if ((v_counter < bitmap.viewport.h) && (reg[1]& 0x40) && (m68k.cycles <= (mcycles_vdp + 860)))
|
|
{
|
|
/* Remap current line */
|
|
render_line(v_counter);
|
|
}
|
|
}
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VSRAM 0x%x write -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
#ifdef LOGERROR
|
|
error("[%d(%d)][%d(%d)] Invalid (%d) 0x%x write -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, code, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Increment address register */
|
|
addr += reg[15];
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* 68k data port access functions (Genesis mode) */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
static void vdp_68k_data_w_m4(unsigned int data)
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Restricted VDP writes during active display */
|
|
if (!(status & 8) && (reg[1] & 0x40))
|
|
{
|
|
/* Update VDP FIFO */
|
|
vdp_fifo_update(m68k.cycles);
|
|
|
|
/* Clear FIFO empty flag */
|
|
status &= 0xFDFF;
|
|
|
|
/* up to 4 words can be stored */
|
|
if (fifo_write_cnt < 4)
|
|
{
|
|
/* Increment FIFO counter */
|
|
fifo_write_cnt++;
|
|
|
|
/* Set FIFO full flag if 4 words are stored */
|
|
status |= ((fifo_write_cnt & 4) << 6);
|
|
}
|
|
else
|
|
{
|
|
/* CPU is halted until last FIFO entry has been processed (Chaos Engine, Soldiers of Fortune, Double Clutch) */
|
|
fifo_lastwrite += fifo_latency;
|
|
m68k.cycles = fifo_lastwrite;
|
|
}
|
|
}
|
|
|
|
/* Check destination code */
|
|
if (code & 0x02)
|
|
{
|
|
/* CRAM index (32 words) */
|
|
int index = addr & 0x1F;
|
|
|
|
/* Pointer to CRAM 9-bit word */
|
|
uint16 *p = (uint16 *)&cram[index << 1];
|
|
|
|
/* Pack 16-bit data (xxx000BBGGRR) to 9-bit CRAM data (xxxBBGGRR) */
|
|
data = ((data & 0xE00) >> 3) | (data & 0x3F);
|
|
|
|
/* Check if CRAM data is being modified */
|
|
if (data != *p)
|
|
{
|
|
/* Write CRAM data */
|
|
*p = data;
|
|
|
|
/* Update color palette */
|
|
color_update_m4(index, data);
|
|
|
|
/* Update backdrop color */
|
|
if (index == (0x10 | (border & 0x0F)))
|
|
{
|
|
color_update_m4(0x40, data);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* VRAM address (interleaved format) */
|
|
int index = ((addr << 1) & 0x3FC) | ((addr & 0x200) >> 8) | (addr & 0x3C00);
|
|
|
|
/* Pointer to VRAM */
|
|
uint16 *p = (uint16 *)&vram[index];
|
|
|
|
/* Byte-swap data if A0 is set */
|
|
if (addr & 1)
|
|
{
|
|
data = ((data >> 8) | (data << 8)) & 0xFFFF;
|
|
}
|
|
|
|
/* Only write unique data to VRAM */
|
|
if (data != *p)
|
|
{
|
|
int name;
|
|
|
|
/* Write data to VRAM */
|
|
*p = data;
|
|
|
|
/* Update the pattern cache */
|
|
MARK_BG_DIRTY (index);
|
|
}
|
|
}
|
|
|
|
/* Increment address register (TODO: check how address is incremented in Mode 4) */
|
|
addr += (reg[15] + 1);
|
|
}
|
|
|
|
static void vdp_68k_data_w_m5(unsigned int data)
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Restricted VDP writes during active display */
|
|
if (!(status & 8) && (reg[1] & 0x40))
|
|
{
|
|
/* Update VDP FIFO */
|
|
vdp_fifo_update(m68k.cycles);
|
|
|
|
/* Clear FIFO empty flag */
|
|
status &= 0xFDFF;
|
|
|
|
/* up to 4 words can be stored */
|
|
if (fifo_write_cnt < 4)
|
|
{
|
|
/* Increment FIFO counter */
|
|
fifo_write_cnt++;
|
|
|
|
/* Set FIFO full flag if 4 words are stored */
|
|
status |= ((fifo_write_cnt & 4) << 6);
|
|
}
|
|
else
|
|
{
|
|
/* CPU is halted until last FIFO entry has been processed (Chaos Engine, Soldiers of Fortune, Double Clutch) */
|
|
fifo_lastwrite += fifo_latency;
|
|
m68k.cycles = fifo_lastwrite;
|
|
}
|
|
}
|
|
|
|
/* Write data */
|
|
vdp_bus_w(data);
|
|
|
|
/* DMA Fill */
|
|
if (dmafill & 0x100)
|
|
{
|
|
/* Fill data = MSB (DMA fill flag is cleared) */
|
|
dmafill = data >> 8;
|
|
|
|
/* DMA length */
|
|
dma_length = (reg[20] << 8) | reg[19];
|
|
|
|
/* Zero DMA length */
|
|
if (!dma_length)
|
|
{
|
|
dma_length = 0x10000;
|
|
}
|
|
|
|
/* Process DMA Fill*/
|
|
dma_type = 2;
|
|
vdp_dma_update(m68k.cycles);
|
|
}
|
|
}
|
|
|
|
static unsigned int vdp_68k_data_r_m4(void)
|
|
{
|
|
/* VRAM address (interleaved format) */
|
|
int index = ((addr << 1) & 0x3FC) | ((addr & 0x200) >> 8) | (addr & 0x3C00);
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Increment address register (TODO: check how address is incremented in Mode 4) */
|
|
addr += (reg[15] + 1);
|
|
|
|
/* Read VRAM data */
|
|
return *(uint16 *) &vram[index];
|
|
}
|
|
|
|
static unsigned int vdp_68k_data_r_m5(void)
|
|
{
|
|
uint16 data = 0;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
switch (code & 0x0F)
|
|
{
|
|
case 0x00: /* VRAM */
|
|
{
|
|
/* Read data */
|
|
data = *(uint16 *)&vram[addr & 0xFFFE];
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VRAM 0x%x read -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
case 0x04: /* VSRAM */
|
|
{
|
|
/* Read data */
|
|
data = *(uint16 *)&vsram[addr & 0x7E];
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VSRAM 0x%x read -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
case 0x08: /* CRAM */
|
|
{
|
|
/* Read data */
|
|
data = *(uint16 *)&cram[addr & 0x7E];
|
|
|
|
/* Unpack 9-bit CRAM data (BBBGGGRRR) to 16-bit bus data (BBB0GGG0RRR0) */
|
|
data = ((data & 0x1C0) << 3) | ((data & 0x038) << 2) | ((data & 0x007) << 1);
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] CRAM 0x%x read -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
case 0x0c: /* undocumented 8-bit VRAM read (cf. http://gendev.spritesmind.net/forum/viewtopic.php?t=790) */
|
|
{
|
|
/* Read data (MSB forced to zero) */
|
|
data = *(uint16 *)&vram[addr & 0xFFFE] & 0xff;
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] 8-bit VRAM 0x%x read -> 0x%x (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, addr, data, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
/* Invalid code value */
|
|
#ifdef LOGERROR
|
|
error("[%d(%d)][%d(%d)] Invalid (%d) 0x%x read (%x)\n", v_counter, m68k.cycles/MCYCLES_PER_LINE-1, m68k.cycles, m68k.cycles%MCYCLES_PER_LINE, code, addr, m68k_get_reg(M68K_REG_PC));
|
|
#endif
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Increment address register */
|
|
addr += reg[15];
|
|
|
|
/* Return data */
|
|
return data;
|
|
}
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* Z80 data port access functions (Master System compatibility mode) */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
static void vdp_z80_data_w_m4(unsigned int data)
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Check destination code */
|
|
if (code & 0x02)
|
|
{
|
|
/* CRAM index (32 words) */
|
|
int index = addr & 0x1F;
|
|
|
|
/* Pointer to CRAM word */
|
|
uint16 *p = (uint16 *)&cram[index << 1];
|
|
|
|
/* Check if CRAM data is being modified */
|
|
if (data != *p)
|
|
{
|
|
/* Write CRAM data */
|
|
*p = data;
|
|
|
|
/* Update color palette */
|
|
color_update_m4(index, data);
|
|
|
|
/* Update backdrop color */
|
|
if (index == (0x10 | (border & 0x0F)))
|
|
{
|
|
color_update_m4(0x40, data);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* VRAM address */
|
|
int index = addr & 0x3FFF;
|
|
|
|
/* Only write unique data to VRAM */
|
|
if (data != vram[index])
|
|
{
|
|
int name;
|
|
|
|
/* Write data */
|
|
vram[index] = data;
|
|
|
|
/* Update pattern cache */
|
|
MARK_BG_DIRTY(index);
|
|
}
|
|
}
|
|
|
|
/* Increment address register (TODO: check how address is incremented in Mode 4) */
|
|
addr += (reg[15] + 1);
|
|
}
|
|
|
|
static void vdp_z80_data_w_m5(unsigned int data)
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Check destination code */
|
|
switch (code & 0x0F)
|
|
{
|
|
case 0x01: /* VRAM */
|
|
{
|
|
/* VRAM address (write low byte to even address & high byte to odd address) */
|
|
int index = addr ^ 1;
|
|
|
|
/* Intercept writes to Sprite Attribute Table */
|
|
if ((index & sat_base_mask) == satb)
|
|
{
|
|
/* Update internal SAT */
|
|
WRITE_BYTE(sat, index & sat_addr_mask, data);
|
|
}
|
|
|
|
/* Only write unique data to VRAM */
|
|
if (data != READ_BYTE(vram, index))
|
|
{
|
|
int name;
|
|
|
|
/* Write data */
|
|
WRITE_BYTE(vram, index, data);
|
|
|
|
/* Update pattern cache */
|
|
MARK_BG_DIRTY (index);
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 0x03: /* CRAM */
|
|
{
|
|
/* Pointer to CRAM word */
|
|
uint16 *p = (uint16 *)&cram[addr & 0x7E];
|
|
|
|
/* Pack 8-bit value into 9-bit CRAM data */
|
|
if (addr & 1)
|
|
{
|
|
/* Write high byte (0000BBB0 -> BBBxxxxxx) */
|
|
data = (*p & 0x3F) | ((data & 0x0E) << 5);
|
|
}
|
|
else
|
|
{
|
|
/* Write low byte (GGG0RRR0 -> xxxGGGRRR) */
|
|
data = (*p & 0x1C0) | ((data & 0x0E) >> 1)| ((data & 0xE0) >> 2);
|
|
}
|
|
|
|
/* Check if CRAM data is being modified */
|
|
if (data != *p)
|
|
{
|
|
/* CRAM index (64 words) */
|
|
int index = (addr >> 1) & 0x3F;
|
|
|
|
/* Write CRAM data */
|
|
*p = data;
|
|
|
|
/* Color entry 0 of each palette is never displayed (transparent pixel) */
|
|
if (index & 0x0F)
|
|
{
|
|
/* Update color palette */
|
|
color_update_m5(index, data);
|
|
}
|
|
|
|
/* Update backdrop color */
|
|
if (index == border)
|
|
{
|
|
color_update_m5(0x00, data);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 0x05: /* VSRAM */
|
|
{
|
|
/* Write low byte to even address & high byte to odd address */
|
|
WRITE_BYTE(vsram, (addr & 0x7F) ^ 1, data);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Increment address register */
|
|
addr += reg[15];
|
|
|
|
/* DMA Fill */
|
|
if (dmafill & 0x100)
|
|
{
|
|
/* Fill data (DMA fill flag is cleared) */
|
|
dmafill = data;
|
|
|
|
/* DMA length */
|
|
dma_length = (reg[20] << 8) | reg[19];
|
|
|
|
/* Zero DMA length */
|
|
if (!dma_length)
|
|
{
|
|
dma_length = 0x10000;
|
|
}
|
|
|
|
/* Process DMA Fill */
|
|
dma_type = 2;
|
|
vdp_dma_update(Z80.cycles);
|
|
}
|
|
}
|
|
|
|
static unsigned int vdp_z80_data_r_m4(void)
|
|
{
|
|
/* Read buffer */
|
|
unsigned int data = fifo[0];
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* Process next read */
|
|
fifo[0] = vram[addr & 0x3FFF];
|
|
|
|
/* Increment address register (TODO: check how address is incremented in Mode 4) */
|
|
addr += (reg[15] + 1);
|
|
|
|
/* Return data */
|
|
return data;
|
|
}
|
|
|
|
static unsigned int vdp_z80_data_r_m5(void)
|
|
{
|
|
unsigned int data = 0;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
switch (code & 0x0F)
|
|
{
|
|
case 0x00: /* VRAM */
|
|
{
|
|
/* Return low byte from even address & high byte from odd address */
|
|
data = READ_BYTE(vram, addr ^ 1);
|
|
break;
|
|
}
|
|
|
|
case 0x04: /* VSRAM */
|
|
{
|
|
/* Return low byte from even address & high byte from odd address */
|
|
data = READ_BYTE(vsram, (addr & 0x7F) ^ 1);
|
|
break;
|
|
}
|
|
|
|
case 0x08: /* CRAM */
|
|
{
|
|
/* Read CRAM data */
|
|
data = *(uint16 *)&cram[addr & 0x7E];
|
|
|
|
/* Unpack 9-bit CRAM data (BBBGGGRRR) to 16-bit data (BBB0GGG0RRR0) */
|
|
data = ((data & 0x1C0) << 3) | ((data & 0x038) << 2) | ((data & 0x007) << 1);
|
|
|
|
/* Return low byte from even address & high byte from odd address */
|
|
if (addr & 1)
|
|
{
|
|
data = data >> 8;
|
|
}
|
|
|
|
data &= 0xFF;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Increment address register */
|
|
addr += reg[15];
|
|
|
|
/* Return data */
|
|
return data;
|
|
}
|
|
|
|
|
|
/*-----------------------------------------------------------------------------*/
|
|
/* VDP specific data port access functions (Master System, Game Gear, SG-1000) */
|
|
/*-----------------------------------------------------------------------------*/
|
|
|
|
static void vdp_z80_data_w_ms(unsigned int data)
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
if (code < 3)
|
|
{
|
|
int index;
|
|
|
|
/* check if we are already on next line */
|
|
int line = (lines_per_frame + (Z80.cycles / MCYCLES_PER_LINE) - 1) % lines_per_frame;
|
|
if ((line > v_counter) && (line < bitmap.viewport.h) && !(work_ram[0x1ffb] & cart.special))
|
|
{
|
|
v_counter = line;
|
|
render_line(line);
|
|
}
|
|
|
|
/* VRAM address */
|
|
index = addr & 0x3FFF;
|
|
|
|
/* VRAM write */
|
|
if (data != vram[index])
|
|
{
|
|
int name;
|
|
vram[index] = data;
|
|
MARK_BG_DIRTY(index);
|
|
}
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VRAM 0x%x write -> 0x%x (%x)\n", v_counter, Z80.cycles/MCYCLES_PER_LINE-1, Z80.cycles, Z80.cycles%MCYCLES_PER_LINE, index, data, Z80.pc.w.l);
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
/* CRAM address */
|
|
int index = addr & 0x1F;
|
|
|
|
/* Pointer to CRAM word */
|
|
uint16 *p = (uint16 *)&cram[index << 1];
|
|
|
|
/* Check if CRAM data is being modified */
|
|
if (data != *p)
|
|
{
|
|
/* Write CRAM data */
|
|
*p = data;
|
|
|
|
/* Update color palette */
|
|
color_update_m4(index, data);
|
|
|
|
/* Update backdrop color */
|
|
if (index == (0x10 | (border & 0x0F)))
|
|
{
|
|
color_update_m4(0x40, data);
|
|
}
|
|
}
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] CRAM 0x%x write -> 0x%x (%x)\n", v_counter, Z80.cycles/MCYCLES_PER_LINE-1, Z80.cycles, Z80.cycles%MCYCLES_PER_LINE, addr, data, Z80.pc.w.l);
|
|
#endif
|
|
}
|
|
|
|
/* Update read buffer */
|
|
fifo[0] = data;
|
|
|
|
/* Update address register */
|
|
addr++;
|
|
}
|
|
|
|
static void vdp_z80_data_w_gg(unsigned int data)
|
|
{
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
if (code < 3)
|
|
{
|
|
int index;
|
|
|
|
/* check if we are already on next line*/
|
|
int line = (lines_per_frame + (Z80.cycles / MCYCLES_PER_LINE) - 1) % lines_per_frame;
|
|
if ((line > v_counter) && (line < bitmap.viewport.h) && !(work_ram[0x1ffb] & cart.special))
|
|
{
|
|
v_counter = line;
|
|
render_line(line);
|
|
}
|
|
|
|
/* VRAM address */
|
|
index = addr & 0x3FFF;
|
|
|
|
/* VRAM write */
|
|
if (data != vram[index])
|
|
{
|
|
int name;
|
|
vram[index] = data;
|
|
MARK_BG_DIRTY(index);
|
|
}
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VRAM 0x%x write -> 0x%x (%x)\n", v_counter, Z80.cycles/MCYCLES_PER_LINE-1, Z80.cycles, Z80.cycles%MCYCLES_PER_LINE, index, data, Z80.pc.w.l);
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
if (addr & 1)
|
|
{
|
|
/* Pointer to CRAM word */
|
|
uint16 *p = (uint16 *)&cram[addr & 0x3E];
|
|
|
|
/* 12-bit data word */
|
|
data = (data << 8) | cached_write;
|
|
|
|
/* Check if CRAM data is being modified */
|
|
if (data != *p)
|
|
{
|
|
/* Color index (0-31) */
|
|
int index = (addr >> 1) & 0x1F;
|
|
|
|
/* Write CRAM data */
|
|
*p = data;
|
|
|
|
/* Update color palette */
|
|
color_update_m4(index, data);
|
|
|
|
/* Update backdrop color */
|
|
if (index == (0x10 | (border & 0x0F)))
|
|
{
|
|
color_update_m4(0x40, data);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Latch LSB */
|
|
cached_write = data;
|
|
}
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] CRAM 0x%x write -> 0x%x (%x)\n", v_counter, Z80.cycles/MCYCLES_PER_LINE-1, Z80.cycles, Z80.cycles%MCYCLES_PER_LINE, addr, data, Z80.pc.w.l);
|
|
#endif
|
|
}
|
|
|
|
/* Update read buffer */
|
|
fifo[0] = data;
|
|
|
|
/* Update address register */
|
|
addr++;
|
|
}
|
|
|
|
static void vdp_z80_data_w_sg(unsigned int data)
|
|
{
|
|
/* VRAM address */
|
|
int index = addr & 0x3FFF;
|
|
|
|
/* Clear pending flag */
|
|
pending = 0;
|
|
|
|
/* 4K address decoding (cf. tms9918a.txt) */
|
|
if (!(reg[1] & 0x80))
|
|
{
|
|
index = (index & 0x203F) | ((index >> 6) & 0x40) | ((index << 1) & 0x1F80);
|
|
}
|
|
|
|
/* VRAM write */
|
|
vram[index] = data;
|
|
|
|
/* Update address register */
|
|
addr++;
|
|
|
|
#ifdef LOGVDP
|
|
error("[%d(%d)][%d(%d)] VRAM 0x%x write -> 0x%x (%x)\n", v_counter, Z80.cycles/MCYCLES_PER_LINE-1, Z80.cycles, Z80.cycles%MCYCLES_PER_LINE, index, data, Z80.pc.w.l);
|
|
#endif
|
|
}
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
/* DMA operations */
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
/* DMA from 68K bus: $000000-$7FFFFF (external area) */
|
|
static void vdp_dma_68k_ext(unsigned int length)
|
|
{
|
|
uint16 data;
|
|
|
|
/* 68k bus source address */
|
|
uint32 source = (reg[23] << 17) | (dma_src << 1);
|
|
|
|
do
|
|
{
|
|
/* Read data word from 68k bus */
|
|
if (m68k.memory_map[source>>16].read16)
|
|
{
|
|
data = m68k.memory_map[source>>16].read16(source);
|
|
}
|
|
else
|
|
{
|
|
data = *(uint16 *)(m68k.memory_map[source>>16].base + (source & 0xFFFF));
|
|
}
|
|
|
|
/* Increment source address */
|
|
source += 2;
|
|
|
|
/* 128k DMA window */
|
|
source = (reg[23] << 17) | (source & 0x1FFFF);
|
|
|
|
/* Write data word to VRAM, CRAM or VSRAM */
|
|
vdp_bus_w(data);
|
|
}
|
|
while (--length);
|
|
|
|
/* Update DMA source address */
|
|
dma_src = (source >> 1) & 0xffff;
|
|
}
|
|
|
|
/* DMA from 68K bus: $800000-$FFFFFF (internal area) except I/O area */
|
|
static void vdp_dma_68k_ram(unsigned int length)
|
|
{
|
|
uint16 data;
|
|
|
|
/* 68k bus source address */
|
|
uint32 source = (reg[23] << 17) | (dma_src << 1);
|
|
|
|
do
|
|
{
|
|
/* access Work-RAM by default */
|
|
data = *(uint16 *)(work_ram + (source & 0xFFFF));
|
|
|
|
/* Increment source address */
|
|
source += 2;
|
|
|
|
/* 128k DMA window */
|
|
source = (reg[23] << 17) | (source & 0x1FFFF);
|
|
|
|
/* Write data word to VRAM, CRAM or VSRAM */
|
|
vdp_bus_w(data);
|
|
}
|
|
while (--length);
|
|
|
|
/* Update DMA source address */
|
|
dma_src = (source >> 1) & 0xffff;
|
|
}
|
|
|
|
/* DMA from 68K bus: $A00000-$A1FFFF (I/O area) specific */
|
|
static void vdp_dma_68k_io(unsigned int length)
|
|
{
|
|
uint16 data;
|
|
|
|
/* 68k bus source address */
|
|
uint32 source = (reg[23] << 17) | (dma_src << 1);
|
|
|
|
do
|
|
{
|
|
/* Z80 area */
|
|
if (source <= 0xA0FFFF)
|
|
{
|
|
/* Return $FFFF only when the Z80 isn't hogging the Z-bus.
|
|
(e.g. Z80 isn't reset and 68000 has the bus) */
|
|
data = ((zstate ^ 3) ? *(uint16 *)(work_ram + (source & 0xFFFF)) : 0xFFFF);
|
|
}
|
|
|
|
/* The I/O chip and work RAM try to drive the data bus which results
|
|
in both values being combined in random ways when read.
|
|
We return the I/O chip values which seem to have precedence, */
|
|
else if (source <= 0xA1001F)
|
|
{
|
|
data = io_68k_read((source >> 1) & 0x0F);
|
|
data = (data << 8 | data);
|
|
}
|
|
|
|
/* All remaining locations access work RAM */
|
|
else
|
|
{
|
|
data = *(uint16 *)(work_ram + (source & 0xFFFF));
|
|
}
|
|
|
|
/* Increment source address */
|
|
source += 2;
|
|
|
|
/* 128k DMA window */
|
|
source = (reg[23] << 17) | (source & 0x1FFFF);
|
|
|
|
/* Write data to VRAM, CRAM or VSRAM */
|
|
vdp_bus_w(data);
|
|
}
|
|
while (--length);
|
|
|
|
/* Update DMA source address */
|
|
dma_src = (source >> 1) & 0xffff;
|
|
}
|
|
|
|
/* VRAM Copy (TODO: check if CRAM or VSRAM copy is possible) */
|
|
static void vdp_dma_copy(unsigned int length)
|
|
{
|
|
/* VRAM read/write operation only */
|
|
if ((code & 0x1E) == 0x10)
|
|
{
|
|
int name;
|
|
uint8 data;
|
|
|
|
/* VRAM source address */
|
|
uint16 source = dma_src;
|
|
|
|
do
|
|
{
|
|
/* Read byte from source address */
|
|
data = READ_BYTE(vram, source);
|
|
|
|
/* Intercept writes to Sprite Attribute Table */
|
|
if ((addr & sat_base_mask) == satb)
|
|
{
|
|
/* Update internal SAT */
|
|
WRITE_BYTE(sat, addr & sat_addr_mask, data);
|
|
}
|
|
|
|
/* Write byte to VRAM address */
|
|
WRITE_BYTE(vram, addr, data);
|
|
|
|
/* Update pattern cache */
|
|
MARK_BG_DIRTY(addr);
|
|
|
|
/* Increment source address */
|
|
source++;
|
|
|
|
/* Increment VRAM address */
|
|
addr += reg[15];
|
|
}
|
|
while (--length);
|
|
|
|
/* Update DMA source address */
|
|
dma_src = source;
|
|
}
|
|
else
|
|
{
|
|
/* DMA source & VRAM addresses are still incremented */
|
|
addr += reg[15] * length;
|
|
dma_src += length;
|
|
}
|
|
}
|
|
|
|
/* VRAM Fill (TODO: check if CRAM or VSRAM fill is possible) */
|
|
static void vdp_dma_fill(unsigned int length)
|
|
{
|
|
/* VRAM write operation only (Williams Greatest Hits after soft reset) */
|
|
if ((code & 0x1F) == 0x01)
|
|
{
|
|
int name;
|
|
uint8 data = dmafill;
|
|
|
|
do
|
|
{
|
|
/* Intercept writes to Sprite Attribute Table */
|
|
if ((addr & sat_base_mask) == satb)
|
|
{
|
|
/* Update internal SAT */
|
|
WRITE_BYTE(sat, (addr & sat_addr_mask) ^ 1, data);
|
|
}
|
|
|
|
/* Write byte to adjacent VRAM address */
|
|
WRITE_BYTE(vram, addr ^ 1, data);
|
|
|
|
/* Update pattern cache */
|
|
MARK_BG_DIRTY (addr);
|
|
|
|
/* Increment VRAM address */
|
|
addr += reg[15];
|
|
}
|
|
while (--length);
|
|
}
|
|
else
|
|
{
|
|
/* VRAM address is still incremented */
|
|
addr += reg[15] * length;
|
|
}
|
|
}
|