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https://github.com/ekeeke/Genesis-Plus-GX.git
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79 lines
3.1 KiB
C
79 lines
3.1 KiB
C
/***************************************************************************************
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* Genesis Plus
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* CD data controller (LC8951x compatible)
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*
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* Copyright (C) 2012-2024 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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#ifndef _HW_CDC_
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#define _HW_CDC_
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#define cdc scd.cdc_hw
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#define CDC_MAIN_CPU_ACCESS 0x42
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#define CDC_SUB_CPU_ACCESS 0x43
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/* CDC hardware */
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typedef struct
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{
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uint8 ifstat;
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uint8 ifctrl;
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reg16_t dbc;
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reg16_t dac;
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reg16_t pt;
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reg16_t wa;
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uint8 ctrl[2];
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uint8 head[2][4];
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uint8 stat[4];
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unsigned int cycles;
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void (*dma_w)(unsigned int length); /* active DMA callback */
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void (*halted_dma_w)(unsigned int length); /* halted DMA callback */
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uint8 ram[0x4000 + 2352]; /* 16K external RAM (with one block overhead to handle buffer overrun) */
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uint8 ar_mask;
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uint8 irq; /* invert of CDC /INT output */
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} cdc_t;
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/* Function prototypes */
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extern void cdc_init(void);
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extern void cdc_reset(void);
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extern int cdc_context_save(uint8 *state);
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extern int cdc_context_load(uint8 *state);
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extern void cdc_dma_init(void);
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extern void cdc_dma_update(unsigned int cycles);
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extern void cdc_decoder_update(uint32 header);
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extern void cdc_reg_w(unsigned char data);
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extern unsigned char cdc_reg_r(void);
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extern unsigned short cdc_host_r(uint8 cpu_access);
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#endif
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