The-Homebrew-Cloud/Genesis-Plus-GX
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Genesis-Plus-GX/source/cart_hw/eeprom.c
ekeeke31 f2e93d4949 updated Z80 core to last version (fixes IM0 interrupt timing + some BIT instructions) 
added John Madden Football 93 in EEPROM database (fixes backup support)
initiated ROM database for cartridges that uses SRAM (some ROM headers are definitively wrong !), need more...
2009-08-18 16:45:09 +00:00

463 lines
15 KiB
C
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/****************************************************************************
* Genesis Plus
* Serial EEPROM support
*
* Copyright (C) 2007, 2008, 2009 Eke-Eke (GCN/Wii port)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
***************************************************************************/
#include "shared.h"
#define GAME_CNT 28
T_EEPROM eeprom;
typedef struct
{
char game_id[16];
uint16 chk;
T_EEPROM_TYPE type;
} T_GAME_ENTRY;
static const T_GAME_ENTRY database[GAME_CNT] =
{
/* ACCLAIM mappers */
/* 24C02 (old mapper) */
{{"T-081326" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200001, 0, 1, 1}}, /* NBA Jam (UE) */
{{"T-81033" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200001, 0, 1, 1}}, /* NBA Jam (J) */
/* 24C02 */
{{"T-81406" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* NBA Jam TE */
{{"T-081276" }, 0, {8, 0xFF, 0xFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* NFL Quarterback Club */
/* 24C16 */
{{"T-081586" }, 0, {8, 0x7FF, 0x7FF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* NFL Quarterback Club '96 */
/* 24C65 */
{{"T-81576" }, 0, {16, 0x1FFF, 0x1FFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* College Slam */
{{"T-81476" }, 0, {16, 0x1FFF, 0x1FFF, 0x200001, 0x200001, 0x200000, 0, 0, 0}}, /* Frank Thomas Big Hurt Baseball */
/* EA mapper (24C01 only) */
{{"T-50176" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* Rings of Power */
{{"T-50396" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* NHLPA Hockey 93 */
{{"T-50446" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* John Madden Football 93 */
{{"T-50516" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* John Madden Football 93 (Championship Ed.) */
{{"T-50606" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 7, 7, 6}}, /* Bill Walsh College Football */
/* SEGA mapper (24C01 only) */
{{"T-12046" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Megaman - The Wily Wars */
{{"T-12053" }, 0xEA80, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Rockman Mega World (J) [A] */
{{"MK-1215" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Evander 'Real Deal' Holyfield's Boxing */
{{"MK-1228" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Greatest Heavyweights of the Ring (U) */
{{"G-5538" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Greatest Heavyweights of the Ring (J) */
{{"PR-1993" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Greatest Heavyweights of the Ring (E) */
{{"G-4060" }, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Wonderboy in Monster World */
{{"00001211-00"}, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Sports Talk Baseball */
{{"00004076-00"}, 0, {7, 0x7F, 0x7F, 0x200001, 0x200001, 0x200001, 0, 0, 1}}, /* Honoo no Toukyuuji Dodge Danpei */
/* CODEMASTERS mapper */
/* 24C01 */
{{"T-120106"}, 0, {7, 0x7F, 0x7F, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Brian Lara Cricket */
/* 24C08 */
{{"T-120096" }, 0, {8, 0x3FF, 0x3FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines 2 - Turbo Tournament (E) */
{{"00000000-00"}, 0x168B, {8, 0x3FF, 0x3FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines Military */
{{"00000000-00"}, 0xCEE0, {8, 0x3FF, 0x3FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines Military (Bad)*/
/* 24C16 */
{{"00000000-00"}, 0x165E, {8, 0x7FF, 0x7FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines Turbo Tournament 96 */
{{"00000000-00"}, 0x2C41, {8, 0x7FF, 0x7FF, 0x300000, 0x380001, 0x300000, 0, 7, 1}}, /* Micro Machines Turbo Tournament 96 (Bad)*/
/* 24C65 */
{{"T-120146-50"}, 0, {16, 0x1FFF, 0x1FFF, 0x300000, 0x380001, 0x300000, 0, 7, 1}} /* Brian Lara Cricket 96, Shane Warne Cricket */
};
void eeprom_init()
{
int i = 0;
/* initialize eeprom */
memset(&eeprom, 0, sizeof(T_EEPROM));
eeprom.sda = eeprom.old_sda = 1;
eeprom.scl = eeprom.old_scl = 1;
eeprom.state = STAND_BY;
/* no eeprom by default */
sram.custom = 0;
/* look into game database */
while ((i<GAME_CNT) && (!sram.custom))
{
if (strstr(rominfo.product,database[i].game_id) != NULL)
{
/* additional check (Micro Machines, Rockman Mega World) */
if ((database[i].chk == 0) || (database[i].chk == rominfo.checksum))
{
sram.custom = 1;
sram.on = 1;
memcpy(&eeprom.type, &database[i].type, sizeof(T_EEPROM_TYPE));
}
}
i++;
}
/* Game not found in database but header seems to indicate it uses EEPROM */
if (!sram.custom)
{
if ((sram.end - sram.start) < 2)
{
sram.custom = 1;
sram.on = 1;
/* set SEGA mapper as default */
memcpy(&eeprom.type, &database[9].type, sizeof(T_EEPROM_TYPE));
}
}
}
static inline void Detect_START()
{
if (eeprom.old_scl && eeprom.scl)
{
if (eeprom.old_sda && !eeprom.sda)
{
eeprom.cycles = 0;
eeprom.slave_mask = 0;
if (eeprom.type.address_bits == 7)
{
eeprom.word_address = 0;
eeprom.state = GET_WORD_ADR_7BITS;
}
else eeprom.state = GET_SLAVE_ADR;
}
}
}
static inline void Detect_STOP()
{
if (eeprom.old_scl && eeprom.scl)
{
if (!eeprom.old_sda && eeprom.sda)
{
eeprom.state = STAND_BY;
}
}
}
void eeprom_write(uint32 address, uint32 value, uint32 word_access)
{
/* decode SCL and SDA value */
if (word_access)
{
/* 16-bits access */
if (eeprom.type.sda_in_adr == address) eeprom.sda = (value >> (8 + eeprom.type.sda_in_bit)) & 1; /* MSB */
else if (eeprom.type.sda_in_adr == (address | 1)) eeprom.sda = (value >> eeprom.type.sda_in_bit) & 1; /* LSB */
else eeprom.sda = eeprom.old_sda;
if (eeprom.type.scl_adr == address) eeprom.scl = (value >> (8 + eeprom.type.scl_bit)) & 1; /* MSB */
else if (eeprom.type.scl_adr == (address | 1)) eeprom.scl = (value >> eeprom.type.scl_bit) & 1; /* LSB */
else eeprom.scl = eeprom.old_scl;
}
else
{
if (eeprom.type.sda_in_adr == address) eeprom.sda = (value >> eeprom.type.sda_in_bit) & 1;
else eeprom.sda = eeprom.old_sda;
if (eeprom.type.scl_adr == address) eeprom.scl = (value >> eeprom.type.scl_bit) & 1;
else eeprom.scl = eeprom.old_scl;
}
/* EEPROM current state */
switch (eeprom.state)
{
/* Standby Mode */
case STAND_BY:
Detect_START();
Detect_STOP();
break;
/* Suspended Mode */
case WAIT_STOP:
Detect_STOP();
break;
/* Get Word Address 7 bits: MODE-1 only (24C01)
* and R/W bit
*/
case GET_WORD_ADR_7BITS:
Detect_START();
Detect_STOP();
/* look for SCL LOW to HIGH transition */
if (!eeprom.old_scl && eeprom.scl)
{
if (eeprom.cycles == 0) eeprom.cycles ++;
}
/* look for SCL HIGH to LOW transition */
if (eeprom.old_scl && !eeprom.scl && (eeprom.cycles > 0))
{
if (eeprom.cycles < 8)
{
eeprom.word_address |= (eeprom.old_sda << (7 - eeprom.cycles));
}
else if (eeprom.cycles == 8)
{
eeprom.rw = eeprom.old_sda;
}
else
{ /* ACK CYCLE */
eeprom.cycles = 0;
eeprom.word_address &= eeprom.type.size_mask;
eeprom.state = eeprom.rw ? READ_DATA : WRITE_DATA;
}
eeprom.cycles ++;
}
break;
/* Get Slave Address (3bits) : MODE-2 & MODE-3 only (24C01 - 24C512) (0-3bits, depending on the array size)
* or/and Word Address MSB: MODE-2 only (24C04 - 24C16) (0-3bits, depending on the array size)
* and R/W bit
*/
case GET_SLAVE_ADR:
Detect_START();
Detect_STOP();
/* look for SCL LOW to HIGH transition */
if (!eeprom.old_scl && eeprom.scl)
{
if (eeprom.cycles == 0) eeprom.cycles ++;
}
/* look for SCL HIGH to LOW transition */
if (eeprom.old_scl && !eeprom.scl && (eeprom.cycles > 0))
{
if ((eeprom.cycles > 4) && (eeprom.cycles <8))
{
if ((eeprom.type.address_bits == 16) ||
(eeprom.type.size_mask < (1 << (15 - eeprom.cycles))))
{
/* this is a SLAVE ADDRESS bit */
eeprom.slave_mask |= (eeprom.old_sda << (7 - eeprom.cycles));
}
else
{
/* this is a WORD ADDRESS high bit */
if (eeprom.old_sda) eeprom.word_address |= (1 << (15 - eeprom.cycles));
else eeprom.word_address &= ~(1 << (15 - eeprom.cycles));
}
}
else if (eeprom.cycles == 8) eeprom.rw = eeprom.old_sda;
else if (eeprom.cycles > 8)
{
/* ACK CYCLE */
eeprom.cycles = 0;
if (eeprom.type.address_bits == 16)
{
/* two ADDRESS bytes */
eeprom.state = eeprom.rw ? READ_DATA : GET_WORD_ADR_HIGH;
eeprom.slave_mask <<= 16;
}
else
{
/* one ADDRESS byte */
eeprom.state = eeprom.rw ? READ_DATA : GET_WORD_ADR_LOW;
eeprom.slave_mask <<= 8;
}
}
eeprom.cycles ++;
}
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.old_scl && !eeprom.scl)
{
if (eeprom.cycles < 9)
{
if ((eeprom.type.size_mask + 1) < (1 << (17 - eeprom.cycles)))
{
/* ignored bit: slave mask should be right-shifted by one */
eeprom.slave_mask >>= 1;
}
else
{
/* this is a WORD ADDRESS high bit */
if (eeprom.old_sda) eeprom.word_address |= (1 << (16 - eeprom.cycles));
else eeprom.word_address &= ~(1 << (16 - eeprom.cycles));
}
eeprom.cycles ++;
}
else
{
/* ACK CYCLE */
eeprom.cycles = 1;
eeprom.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.old_scl && !eeprom.scl)
{
if (eeprom.cycles < 9)
{
if ((eeprom.type.size_mask + 1) < (1 << (9 - eeprom.cycles)))
{
/* ignored bit (X24C01): slave mask should be right-shifted by one */
eeprom.slave_mask >>= 1;
}
else
{
/* this is a WORD ADDRESS high bit */
if (eeprom.old_sda) eeprom.word_address |= (1 << (8 - eeprom.cycles));
else eeprom.word_address &= ~(1 << (8 - eeprom.cycles));
}
eeprom.cycles ++;
}
else
{
/* ACK CYCLE */
eeprom.cycles = 1;
eeprom.word_address &= eeprom.type.size_mask;
eeprom.state = WRITE_DATA;
}
}
break;
/*
* Read Cycle
*/
case READ_DATA:
Detect_START();
Detect_STOP();
/* look for SCL HIGH to LOW transition */
if (eeprom.old_scl && !eeprom.scl)
{
if (eeprom.cycles < 9) eeprom.cycles ++;
else
{
eeprom.cycles = 1;
/* ACK not received */
if (eeprom.old_sda) eeprom.state = WAIT_STOP;
}
}
break;
/*
* Write Cycle
*/
case WRITE_DATA:
Detect_START();
Detect_STOP();
/* look for SCL HIGH to LOW transition */
if (eeprom.old_scl && !eeprom.scl)
{
if (eeprom.cycles < 9)
{
/* Write DATA bits (max 64kBytes) */
uint16 sram_address = (eeprom.slave_mask | eeprom.word_address) & 0xFFFF;
if (eeprom.old_sda) sram.sram[sram_address] |= (1 << (8 - eeprom.cycles));
else sram.sram[sram_address] &= ~(1 << (8 - eeprom.cycles));
if (eeprom.cycles == 8)
{
/* WORD ADDRESS is incremented (roll up at maximum pagesize) */
eeprom.word_address = (eeprom.word_address & (0xFFFF - eeprom.type.pagewrite_mask)) |
((eeprom.word_address + 1) & eeprom.type.pagewrite_mask);
}
eeprom.cycles ++;
}
else eeprom.cycles = 1; /* ACK cycle */
}
break;
}
eeprom.old_scl = eeprom.scl;
eeprom.old_sda = eeprom.sda;
}
uint32 eeprom_read(uint32 address, uint32 word_access)
{
uint8 sda_out = eeprom.sda;
/* EEPROM state */
switch (eeprom.state)
{
case READ_DATA:
if (eeprom.cycles < 9)
{
/* Return DATA bits (max 64kBytes) */
uint16 sram_address = (eeprom.slave_mask | eeprom.word_address) & 0xffff;
sda_out = (sram.sram[sram_address] >> (8 - eeprom.cycles)) & 1;
if (eeprom.cycles == 8)
{
/* WORD ADDRESS is incremented (roll up at maximum array size) */
eeprom.word_address ++;
eeprom.word_address &= eeprom.type.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.cycles == 9) sda_out = 0;
break;
default:
break;
}
/* memory access */
if (word_access)
{
/* 16-bits access */
if (eeprom.type.sda_out_adr & 1) return (sda_out << eeprom.type.sda_out_bit); /* LSB */
else return (sda_out << (eeprom.type.sda_out_bit + 8)); /* MSB */
}
else return (sda_out << eeprom.type.sda_out_bit);
}
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