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https://github.com/ekeeke/Genesis-Plus-GX.git
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f2a7b4cb8a
--------------- * added support for CUE files * added CD-DA tracks emulation (needs CUE+BIN or ISO+WAV images) * added CD fader emulation * added CDD "Fast FW" & "Fast RW" commands emulation * improved CDD TOC emulation (random freezes in Sonic CD, Switch/Panic, Final Fight CD and probably many others) * improved PCM chip synchronization with SUB-CPU (missing speeches in Willy Beamish) * fixed PCM chip emulation (random hangs in Snatcher, missing sound effects in Switch/Panic, Final Fight CD, Wonderdog...) * fixed Word-RAM memory mode on soft-reset (missing logo gfx effects) * fixed SUB-CPU access to unused areas when using PC-relative instructions (Final Fight CD first boss random crash) * fixed CPU idle loop detection on memory mode register access (Pugsy CD first boss slowdown) * fixed Mode 1 emulation (cartridge boot mode) [Core/Sound] --------------- * replaced FIR resampler by Blip Buffer for FM resampling * modified SN76489 core for use of Blip Buffer * improved PSG & FM chips synchronization using Blip Buffer * added Game Gear PSG stereo support * fixed SG-1000 specific PSG noise * fixed YM2612 LFO AM waveform (California Games surfing event) * fixed YM2612 phase precision * minor optimizations to YM2612 core [Core/Game Gear] --------------- * added support for CJ Elephant Fugitive (recently released by SMS Power) * added Game Gear extended screen option [Core/Genesis] --------------- * added support for a few recently dumped (but unreleased) games [Core/General] --------------- * improved ROM & CD image file loading * various code cleanup [Gamecube/Wii] --------------- * added automatic disc swap feature * removed automatic frameskipping (no use) * improved general audio/video sync * various code cleanup & bugfixes
622 lines
21 KiB
C
622 lines
21 KiB
C
/****************************************************************************
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* Genesis Plus
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* I2C Serial EEPROM (24Cxx) support
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*
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* Copyright (C) 2007-2011 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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#define GAME_CNT 28
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/* this defines the type of EEPROM inside the game cartridge as Backup RAM
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*
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* Here are some notes from 8BitWizard (http://www.spritesmind.net/_GenDev/forum):
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*
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* Mode 1 (7-bit) - the chip takes a single byte with a 7-bit memory address and a R/W bit (24C01)
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* Mode 2 (8-bit) - the chip takes a 7-bit device address and R/W bit followed by an 8-bit memory address;
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* the device address may contain up to three more memory address bits (24C01 - 24C16).
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* You can also string eight 24C01, four 24C02, two 24C08, or various combinations, set their address config lines correctly,
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* and the result appears exactly the same as a 24C16
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* Mode 3 (16-bit) - the chip takes a 7-bit device address and R/W bit followed by a 16-bit memory address (24C32 and larger)
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*
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* Also, while most 24Cxx are addressed at 200000-2FFFFF, I have found two different ways of mapping the control lines.
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* EA uses SDA on D7 (read/write) and SCL on D6 (write only), and I have found boards using different mapping (I think Accolade)
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* which uses D1-read=SDA, D0-write=SDA, D1-write=SCL. Accolade also has a custom-chip mapper which may even use a third method.
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*/
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typedef struct
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{
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uint8 address_bits; /* number of bits needed to address memory: 7, 8 or 16 */
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uint16 size_mask; /* depends on the max size of the memory (in bytes) */
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uint16 pagewrite_mask; /* depends on the maximal number of bytes that can be written in a single write cycle */
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uint32 sda_in_adr; /* 68000 memory address mapped to SDA_IN */
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uint32 sda_out_adr; /* 68000 memory address mapped to SDA_OUT */
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uint32 scl_adr; /* 68000 memory address mapped to SCL */
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uint8 sda_in_bit; /* bit offset for SDA_IN */
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uint8 sda_out_bit; /* bit offset for SDA_OUT */
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uint8 scl_bit; /* bit offset for SCL */
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} T_CONFIG_I2C;
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typedef enum
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{
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STAND_BY = 0,
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WAIT_STOP,
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GET_SLAVE_ADR,
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GET_WORD_ADR_7BITS,
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GET_WORD_ADR_HIGH,
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GET_WORD_ADR_LOW,
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WRITE_DATA,
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READ_DATA
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} T_STATE_I2C;
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typedef struct
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{
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uint8 sda; /* current /SDA line state */
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uint8 scl; /* current /SCL line state */
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uint8 old_sda; /* previous /SDA line state */
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uint8 old_scl; /* previous /SCL line state */
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uint8 cycles; /* current operation cycle number (0-9) */
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uint8 rw; /* operation type (1:READ, 0:WRITE) */
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uint16 slave_mask; /* device address (shifted by the memory address width)*/
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uint16 word_address; /* memory address */
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T_STATE_I2C state; /* current operation state */
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T_CONFIG_I2C config; /* EEPROM characteristics for this game */
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} T_EEPROM_I2C;
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typedef struct
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{
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char game_id[16];
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uint16 chk;
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T_CONFIG_I2C config;
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} T_GAME_ENTRY;
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static const T_GAME_ENTRY database[GAME_CNT] =
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{
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/* ACCLAIM mappers */
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/* 24C02 (old mapper) */
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{{"T-081326" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200001, 0, 1, 1}}, /* NBA Jam (UE) */
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{{"T-81033" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200001, 0, 1, 1}}, /* NBA Jam (J) */
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/* 24C02 */
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{{"T-081276" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* NFL Quarterback Club */
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/* 24C04 */
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{{"T-81406" }, 0, {8, 0x1FF, 0x1FF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* NBA Jam TE */
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/* 24C16 */
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{{"T-081586" }, 0, {8, 0x7FF, 0x7FF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* NFL Quarterback Club '96 */
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/* 24C65 */
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{{"T-81576" }, 0, {16, 0x1FFF, 0x1FFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* College Slam */
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{{"T-81476" }, 0, {16, 0x1FFF, 0x1FFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* Frank Thomas Big Hurt Baseball */
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/* EA mapper (X24C01 only) */
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{{"T-50176" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* Rings of Power */
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{{"T-50396" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* NHLPA Hockey 93 */
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{{"T-50446" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* John Madden Football 93 */
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{{"T-50516" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* John Madden Football 93 (Championship Ed.) */
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{{"T-50606" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* Bill Walsh College Football */
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/* SEGA mapper (X24C01 only) */
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{{"T-12046" }, 0xAD23, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Megaman - The Wily Wars */
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{{"T-12053" }, 0xEA80, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Rockman Mega World [Alt] */
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{{"MK-1215" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Evander 'Real Deal' Holyfield's Boxing */
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{{"MK-1228" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Greatest Heavyweights of the Ring (U) */
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{{"G-5538" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Greatest Heavyweights of the Ring (J) */
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{{"PR-1993" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Greatest Heavyweights of the Ring (E) */
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{{"G-4060" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Wonderboy in Monster World */
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{{"00001211-00"}, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Sports Talk Baseball */
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{{"00004076-00"}, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Honoo no Toukyuuji Dodge Danpei */
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{{"G-4524" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Ninja Burai Densetsu */
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{{"00054503-00"}, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Game Toshokan */
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/* CODEMASTERS mapper */
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/* 24C08 */
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{{"T-120106" }, 0, {8, 0x3FF, 0x3FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Brian Lara Cricket */
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{{"00000000-00"}, 0xCEE0, {8, 0x3FF, 0x3FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines Military */
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/* 24C16 */
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{{"T-120096" }, 0, {8, 0x7FF, 0x7FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines 2 - Turbo Tournament */
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{{"00000000-00"}, 0x2C41, {8, 0x7FF, 0x7FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines Turbo Tournament 96 */
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/* 24C65 */
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{{"T-120146-50"}, 0, {16, 0x1FFF, 0x1FFF, 0x300000, 0x380001, 0x300000, 0, 7, 1}} /* Brian Lara Cricket 96, Shane Warne Cricket */
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};
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static T_EEPROM_I2C eeprom_i2c;
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static unsigned int eeprom_i2c_read_byte(unsigned int address);
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static unsigned int eeprom_i2c_read_word(unsigned int address);
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static void eeprom_i2c_write_byte(unsigned int address, unsigned int data);
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static void eeprom_i2c_write_word(unsigned int address, unsigned int data);
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void eeprom_i2c_init()
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{
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int i = 0;
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/* initialize eeprom */
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memset(&eeprom_i2c, 0, sizeof(T_EEPROM_I2C));
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eeprom_i2c.sda = eeprom_i2c.old_sda = 1;
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eeprom_i2c.scl = eeprom_i2c.old_scl = 1;
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eeprom_i2c.state = STAND_BY;
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/* no eeprom by default */
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sram.custom = 0;
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/* look into game database */
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while (i<GAME_CNT)
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{
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if (strstr(rominfo.product,database[i].game_id) != NULL)
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{
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/* additional check (Micro Machines, Rockman Mega World) */
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if ((database[i].chk == 0x0000) || (database[i].chk == rominfo.realchecksum))
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{
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sram.custom = 1;
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sram.on = 1;
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memcpy(&eeprom_i2c.config, &database[i].config, sizeof(T_CONFIG_I2C));
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i = GAME_CNT;
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}
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}
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i++;
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}
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/* Game not found in database but ROM header indicates it uses EEPROM */
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if (!sram.custom && sram.detected)
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{
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if ((sram.end - sram.start) < 2)
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{
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/* set SEGA mapper as default */
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sram.custom = 1;
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memcpy(&eeprom_i2c.config, &database[9].config, sizeof(T_CONFIG_I2C));
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}
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}
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/* initialize m68k bus handlers */
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if (sram.custom)
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{
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m68k.memory_map[eeprom_i2c.config.sda_out_adr >> 16].read8 = eeprom_i2c_read_byte;
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m68k.memory_map[eeprom_i2c.config.sda_out_adr >> 16].read16 = eeprom_i2c_read_word;
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m68k.memory_map[eeprom_i2c.config.sda_in_adr >> 16].read8 = eeprom_i2c_read_byte;
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m68k.memory_map[eeprom_i2c.config.sda_in_adr >> 16].read16 = eeprom_i2c_read_word;
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m68k.memory_map[eeprom_i2c.config.scl_adr >> 16].write8 = eeprom_i2c_write_byte;
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m68k.memory_map[eeprom_i2c.config.scl_adr >> 16].write16 = eeprom_i2c_write_word;
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zbank_memory_map[eeprom_i2c.config.sda_out_adr >> 16].read = eeprom_i2c_read_byte;
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zbank_memory_map[eeprom_i2c.config.sda_in_adr >> 16].read = eeprom_i2c_read_byte;
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zbank_memory_map[eeprom_i2c.config.scl_adr >> 16].write = eeprom_i2c_write_byte;
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}
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}
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INLINE void Detect_START()
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{
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if (eeprom_i2c.old_scl && eeprom_i2c.scl)
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{
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if (eeprom_i2c.old_sda && !eeprom_i2c.sda)
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{
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eeprom_i2c.cycles = 0;
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eeprom_i2c.slave_mask = 0;
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if (eeprom_i2c.config.address_bits == 7)
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{
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eeprom_i2c.word_address = 0;
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eeprom_i2c.state = GET_WORD_ADR_7BITS;
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}
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else eeprom_i2c.state = GET_SLAVE_ADR;
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}
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}
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}
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INLINE void Detect_STOP()
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{
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if (eeprom_i2c.old_scl && eeprom_i2c.scl)
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{
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if (!eeprom_i2c.old_sda && eeprom_i2c.sda)
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{
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eeprom_i2c.state = STAND_BY;
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}
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}
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}
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static void eeprom_i2c_update(void)
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{
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/* EEPROM current state */
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switch (eeprom_i2c.state)
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{
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/* Standby Mode */
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case STAND_BY:
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{
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Detect_START();
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Detect_STOP();
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break;
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}
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/* Suspended Mode */
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case WAIT_STOP:
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{
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Detect_STOP();
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break;
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}
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/* Get Word Address 7 bits: MODE-1 only (24C01)
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* and R/W bit
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*/
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case GET_WORD_ADR_7BITS:
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{
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Detect_START();
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Detect_STOP();
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/* look for SCL LOW to HIGH transition */
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if (!eeprom_i2c.old_scl && eeprom_i2c.scl)
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{
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if (eeprom_i2c.cycles == 0) eeprom_i2c.cycles ++;
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}
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/* look for SCL HIGH to LOW transition */
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if (eeprom_i2c.old_scl && !eeprom_i2c.scl && (eeprom_i2c.cycles > 0))
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{
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if (eeprom_i2c.cycles < 8)
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{
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eeprom_i2c.word_address |= (eeprom_i2c.old_sda << (7 - eeprom_i2c.cycles));
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}
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else if (eeprom_i2c.cycles == 8)
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{
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eeprom_i2c.rw = eeprom_i2c.old_sda;
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}
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else
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{ /* ACK CYCLE */
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eeprom_i2c.cycles = 0;
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eeprom_i2c.word_address &= eeprom_i2c.config.size_mask;
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eeprom_i2c.state = eeprom_i2c.rw ? READ_DATA : WRITE_DATA;
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}
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eeprom_i2c.cycles ++;
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}
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break;
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}
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/* Get Slave Address (3bits) : MODE-2 & MODE-3 only (24C01 - 24C512) (0-3bits, depending on the array size)
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* or/and Word Address MSB: MODE-2 only (24C04 - 24C16) (0-3bits, depending on the array size)
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* and R/W bit
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*/
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case GET_SLAVE_ADR:
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{
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Detect_START();
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Detect_STOP();
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/* look for SCL LOW to HIGH transition */
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if (!eeprom_i2c.old_scl && eeprom_i2c.scl)
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{
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if (eeprom_i2c.cycles == 0) eeprom_i2c.cycles ++;
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}
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/* look for SCL HIGH to LOW transition */
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if (eeprom_i2c.old_scl && !eeprom_i2c.scl && (eeprom_i2c.cycles > 0))
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{
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if ((eeprom_i2c.cycles > 4) && (eeprom_i2c.cycles <8))
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{
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if ((eeprom_i2c.config.address_bits == 16) ||
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(eeprom_i2c.config.size_mask < (1 << (15 - eeprom_i2c.cycles))))
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{
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/* this is a SLAVE ADDRESS bit */
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eeprom_i2c.slave_mask |= (eeprom_i2c.old_sda << (7 - eeprom_i2c.cycles));
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}
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else
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{
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/* this is a WORD ADDRESS high bit */
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if (eeprom_i2c.old_sda) eeprom_i2c.word_address |= (1 << (15 - eeprom_i2c.cycles));
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else eeprom_i2c.word_address &= ~(1 << (15 - eeprom_i2c.cycles));
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}
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}
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else if (eeprom_i2c.cycles == 8) eeprom_i2c.rw = eeprom_i2c.old_sda;
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else if (eeprom_i2c.cycles > 8)
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{
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/* ACK CYCLE */
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eeprom_i2c.cycles = 0;
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if (eeprom_i2c.config.address_bits == 16)
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{
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/* two ADDRESS bytes */
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eeprom_i2c.state = eeprom_i2c.rw ? READ_DATA : GET_WORD_ADR_HIGH;
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eeprom_i2c.slave_mask <<= 16;
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}
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else
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{
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/* one ADDRESS byte */
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eeprom_i2c.state = eeprom_i2c.rw ? READ_DATA : GET_WORD_ADR_LOW;
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eeprom_i2c.slave_mask <<= 8;
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}
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}
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eeprom_i2c.cycles ++;
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}
|
|
break;
|
|
}
|
|
|
|
/* Get Word Address MSB (4-8bits depending on the array size)
|
|
* MODE-3 only (24C32 - 24C512)
|
|
*/
|
|
case GET_WORD_ADR_HIGH:
|
|
{
|
|
Detect_START();
|
|
Detect_STOP();
|
|
|
|
/* look for SCL HIGH to LOW transition */
|
|
if (eeprom_i2c.old_scl && !eeprom_i2c.scl)
|
|
{
|
|
if (eeprom_i2c.cycles < 9)
|
|
{
|
|
if ((eeprom_i2c.config.size_mask + 1) < (1 << (17 - eeprom_i2c.cycles)))
|
|
{
|
|
/* ignored bit: slave mask should be right-shifted by one */
|
|
eeprom_i2c.slave_mask >>= 1;
|
|
}
|
|
else
|
|
{
|
|
/* this is a WORD ADDRESS high bit */
|
|
if (eeprom_i2c.old_sda) eeprom_i2c.word_address |= (1 << (16 - eeprom_i2c.cycles));
|
|
else eeprom_i2c.word_address &= ~(1 << (16 - eeprom_i2c.cycles));
|
|
}
|
|
|
|
eeprom_i2c.cycles ++;
|
|
}
|
|
else
|
|
{
|
|
/* ACK CYCLE */
|
|
eeprom_i2c.cycles = 1;
|
|
eeprom_i2c.state = GET_WORD_ADR_LOW;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* Get Word Address LSB: 7bits (24C01) or 8bits (24C02-24C512)
|
|
* MODE-2 and MODE-3 only (24C01 - 24C512)
|
|
*/
|
|
case GET_WORD_ADR_LOW:
|
|
{
|
|
Detect_START();
|
|
Detect_STOP();
|
|
|
|
/* look for SCL HIGH to LOW transition */
|
|
if (eeprom_i2c.old_scl && !eeprom_i2c.scl)
|
|
{
|
|
if (eeprom_i2c.cycles < 9)
|
|
{
|
|
if ((eeprom_i2c.config.size_mask + 1) < (1 << (9 - eeprom_i2c.cycles)))
|
|
{
|
|
/* ignored bit (X24C01): slave mask should be right-shifted by one */
|
|
eeprom_i2c.slave_mask >>= 1;
|
|
}
|
|
else
|
|
{
|
|
/* this is a WORD ADDRESS high bit */
|
|
if (eeprom_i2c.old_sda) eeprom_i2c.word_address |= (1 << (8 - eeprom_i2c.cycles));
|
|
else eeprom_i2c.word_address &= ~(1 << (8 - eeprom_i2c.cycles));
|
|
}
|
|
|
|
eeprom_i2c.cycles ++;
|
|
}
|
|
else
|
|
{
|
|
/* ACK CYCLE */
|
|
eeprom_i2c.cycles = 1;
|
|
eeprom_i2c.word_address &= eeprom_i2c.config.size_mask;
|
|
eeprom_i2c.state = WRITE_DATA;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Read Cycle
|
|
*/
|
|
case READ_DATA:
|
|
{
|
|
Detect_START();
|
|
Detect_STOP();
|
|
|
|
/* look for SCL HIGH to LOW transition */
|
|
if (eeprom_i2c.old_scl && !eeprom_i2c.scl)
|
|
{
|
|
if (eeprom_i2c.cycles < 9) eeprom_i2c.cycles ++;
|
|
else
|
|
{
|
|
eeprom_i2c.cycles = 1;
|
|
|
|
/* ACK not received */
|
|
if (eeprom_i2c.old_sda) eeprom_i2c.state = WAIT_STOP;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Write Cycle
|
|
*/
|
|
case WRITE_DATA:
|
|
{
|
|
Detect_START();
|
|
Detect_STOP();
|
|
|
|
/* look for SCL HIGH to LOW transition */
|
|
if (eeprom_i2c.old_scl && !eeprom_i2c.scl)
|
|
{
|
|
if (eeprom_i2c.cycles < 9)
|
|
{
|
|
/* Write DATA bits (max 64kBytes) */
|
|
uint16 sram_address = (eeprom_i2c.slave_mask | eeprom_i2c.word_address) & 0xFFFF;
|
|
if (eeprom_i2c.old_sda) sram.sram[sram_address] |= (1 << (8 - eeprom_i2c.cycles));
|
|
else sram.sram[sram_address] &= ~(1 << (8 - eeprom_i2c.cycles));
|
|
|
|
if (eeprom_i2c.cycles == 8)
|
|
{
|
|
/* WORD ADDRESS is incremented (roll up at maximum pagesize) */
|
|
eeprom_i2c.word_address = (eeprom_i2c.word_address & (0xFFFF - eeprom_i2c.config.pagewrite_mask)) |
|
|
((eeprom_i2c.word_address + 1) & eeprom_i2c.config.pagewrite_mask);
|
|
}
|
|
|
|
eeprom_i2c.cycles ++;
|
|
}
|
|
else eeprom_i2c.cycles = 1; /* ACK cycle */
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
eeprom_i2c.old_scl = eeprom_i2c.scl;
|
|
eeprom_i2c.old_sda = eeprom_i2c.sda;
|
|
}
|
|
|
|
static unsigned char eeprom_i2c_out(void)
|
|
{
|
|
uint8 sda_out = eeprom_i2c.sda;
|
|
|
|
/* EEPROM state */
|
|
switch (eeprom_i2c.state)
|
|
{
|
|
case READ_DATA:
|
|
{
|
|
if (eeprom_i2c.cycles < 9)
|
|
{
|
|
/* Return DATA bits (max 64kBytes) */
|
|
uint16 sram_address = (eeprom_i2c.slave_mask | eeprom_i2c.word_address) & 0xffff;
|
|
sda_out = (sram.sram[sram_address] >> (8 - eeprom_i2c.cycles)) & 1;
|
|
|
|
if (eeprom_i2c.cycles == 8)
|
|
{
|
|
/* WORD ADDRESS is incremented (roll up at maximum array size) */
|
|
eeprom_i2c.word_address ++;
|
|
eeprom_i2c.word_address &= eeprom_i2c.config.size_mask;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case GET_WORD_ADR_7BITS:
|
|
case GET_SLAVE_ADR:
|
|
case GET_WORD_ADR_HIGH:
|
|
case GET_WORD_ADR_LOW:
|
|
case WRITE_DATA:
|
|
{
|
|
if (eeprom_i2c.cycles == 9) sda_out = 0;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
|
|
return (sda_out << eeprom_i2c.config.sda_out_bit);
|
|
}
|
|
|
|
static unsigned int eeprom_i2c_read_byte(unsigned int address)
|
|
{
|
|
if (address == eeprom_i2c.config.sda_out_adr)
|
|
{
|
|
return eeprom_i2c_out();
|
|
}
|
|
|
|
return READ_BYTE(cart.rom, address);
|
|
}
|
|
|
|
static unsigned int eeprom_i2c_read_word(unsigned int address)
|
|
{
|
|
if (address == eeprom_i2c.config.sda_out_adr)
|
|
{
|
|
return (eeprom_i2c_out() << 8);
|
|
}
|
|
|
|
if (address == (eeprom_i2c.config.sda_out_adr ^ 1))
|
|
{
|
|
return eeprom_i2c_out();
|
|
}
|
|
|
|
return *(uint16 *)(cart.rom + address);
|
|
}
|
|
|
|
static void eeprom_i2c_write_byte(unsigned int address, unsigned int data)
|
|
{
|
|
int do_update = 0;
|
|
|
|
if (address == eeprom_i2c.config.sda_in_adr)
|
|
{
|
|
eeprom_i2c.sda = (data >> eeprom_i2c.config.sda_in_bit) & 1;
|
|
do_update = 1;
|
|
}
|
|
|
|
if (address == eeprom_i2c.config.scl_adr)
|
|
{
|
|
eeprom_i2c.scl = (data >> eeprom_i2c.config.scl_bit) & 1;
|
|
do_update = 1;
|
|
}
|
|
|
|
if (do_update)
|
|
{
|
|
eeprom_i2c_update();
|
|
return;
|
|
}
|
|
|
|
m68k_unused_8_w(address, data);
|
|
}
|
|
|
|
static void eeprom_i2c_write_word(unsigned int address, unsigned int data)
|
|
{
|
|
int do_update = 0;
|
|
|
|
if (address == eeprom_i2c.config.sda_in_adr)
|
|
{
|
|
eeprom_i2c.sda = (data >> (8 + eeprom_i2c.config.sda_in_bit)) & 1;
|
|
do_update = 1;
|
|
}
|
|
else if (address == (eeprom_i2c.config.sda_in_adr ^1))
|
|
{
|
|
eeprom_i2c.sda = (data >> eeprom_i2c.config.sda_in_bit) & 1;
|
|
do_update = 1;
|
|
}
|
|
|
|
if (address == eeprom_i2c.config.scl_adr)
|
|
{
|
|
eeprom_i2c.scl = (data >> (8 + eeprom_i2c.config.scl_bit)) & 1;
|
|
do_update = 1;
|
|
}
|
|
else if (address == (eeprom_i2c.config.scl_adr ^1))
|
|
{
|
|
eeprom_i2c.scl = (data >> eeprom_i2c.config.scl_bit) & 1;
|
|
do_update = 1;
|
|
}
|
|
|
|
if (do_update)
|
|
{
|
|
eeprom_i2c_update();
|
|
return;
|
|
}
|
|
|
|
m68k_unused_16_w(address, data);
|
|
}
|