INL-retro-progdump/firmware/source/sega.c

458 lines
8.4 KiB
C

#include "sega.h"
//only need this file if connector is present on the device
#ifdef SEGA_CONN
uint16_t sega_addr = 0;
//=================================================================================================
//
// SEGA operations
// This file includes all the sega functions possible to be called from the sega dictionary.
//
// See description of the commands contained here in shared/shared_dictionaries.h
//
//=================================================================================================
/* Desc:Function takes an opcode which was transmitted via USB
* then decodes it to call designated function.
* shared_dict_sega.h is used in both host and fw to ensure opcodes/names align
* Pre: Macros must be defined in firmware pinport.h
* opcode must be defined in shared_dict_sega.h
* Post:function call complete.
* Rtn: SUCCESS if opcode found and completed, error if opcode not present or other problem.
*/
uint8_t sega_call( uint8_t opcode, uint8_t miscdata, uint16_t operand, uint8_t *rdata )
{
#define RD_LEN 0
#define RD0 1
#define RD1 2
#define BYTE_LEN 1
#define HWORD_LEN 2
uint16_t temp;
switch (opcode) {
// //no return value:
case GEN_SET_ADDR:
sega_addr = operand;
ADDR_SET(sega_addr);
break;
case GEN_WR_LO:
sega_addr = operand;
gen_wr_lo( operand, miscdata );
break;
case GEN_WR_HI:
sega_addr = operand;
gen_wr_hi( operand, miscdata );
break;
case GEN_SET_BANK:
temp = ADDR_CUR; //this will get stomped
#define LOMEM_TIME_MASK 0x84
//A17-18, 20-23
FFADDR_SET( operand | LOMEM_TIME_MASK ); //TODO decode #TIME & LO_MEM
ADDR_SET(temp); //restore A1-16
#define SEGA_A19_MASK 0x04
//A19
if ( operand & SEGA_A19_MASK ) {
IRQ_HI();
} else {
IRQ_LO();
}
//use of flip-flop corrupts A1-A16, restore it
ADDR_SET(sega_addr);
break;
case GEN_FLASH_WR_ADDROFF:
sega_addr += miscdata;
gen_flash_wr(sega_addr, operand);
break;
case GEN_SST_FLASH_WR_ADDROFF:
sega_addr += miscdata;
gen_sst_flash_wr(sega_addr, operand);
break;
//8bit return values:
case GEN_ROM_RD:
sega_addr = operand;
rdata[RD_LEN] = HWORD_LEN;
temp = gen_rom_rd( operand );
rdata[RD0] = temp;
rdata[RD1] = temp>>8;
break;
default:
//macro doesn't exist
return ERR_UNKN_SEGA_OPCODE;
}
return SUCCESS;
}
uint16_t gen_rom_rd( uint16_t addr )
{
uint16_t rv;
uint8_t temp;
ADDR_SET(addr);
//set #C_CE
ROMSEL_LO();
//set #C_OE
CSRD_LO();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//6 above were working, trying more
//NOP();
//NOP();
//NOP();
//NOP();
//NOP();
//NOP();
////latch data high byte
//rv = HDATA_VAL;
////shift into upper byte
//rv = rv<<8;
////latch data low byte
//DATA_RD(temp);
//rv |= temp;
DATA16H_RD(rv);
rv = rv << 8;
DATA16L_RD(temp);
rv |= temp;
//return bus to default
CSRD_HI();
ROMSEL_HI();
return rv;
}
void gen_wr_lo( uint16_t addr, uint8_t data )
{
ADDR_SET(addr);
//put data on bus
DATA_OP();
DATA_SET(data); //lower byte D0-7
//set #C_CE
ROMSEL_LO();
//set #C_OE
//CSRD_LO();
//set #LDSW
PRGRW_LO();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//latch data with /WE - #LDSW
PRGRW_HI();
//return bus to default
//CSRD_HI();
ROMSEL_HI();
//Free data bus
DATA_IP();
}
//TODO this function is untested, but I think it'll work..
void gen_wr_hi( uint16_t addr, uint8_t data )
{
ADDR_SET(addr);
//put data on bus
//DATA_OP();
//DATA_SET(data); //lower byte D0-7
//set data bus to output
//TODO maybe want a function that only sets upper byte to output..?
DATA16_OP();
//DATA16L_SET(data);
DATA16H_SET(data); //put 8bits of data on high byte
//set #C_CE
ROMSEL_LO(); //enables level shifter
//wait for data to get to flash before latching
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//set #UDSW
CSWR_LO();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//latch data with /WE - #UDSW
CSWR_HI();
NOP();
NOP();
NOP();
//return bus to default
ROMSEL_HI();
//Free data bus
DATA16_IP();
}
void gen_flash_wr( uint16_t addr, uint16_t data )
{
uint8_t temp = data;
ADDR_SET(addr);
//put data on bus
//DATA_OP();
//DATA_SET(temp); //lower byte D0-7
DATA16_OP();
DATA16L_SET(data);
data = data>>8;
DATA16H_SET(data); //put 8bits of data on high byte
//TODO figure out why this is needed...
//guessing macro expansion or something with setting both bytes separately
DATA_SET(temp); //lower byte D0-7
//TODO set upper byte of data
//set #C_CE
ROMSEL_LO();
//set #C_OE
//flash writes must be high
//CSRD_LO();
//set #LDSW
//PRGRW_LO();
// #UDSW B29 CPU D8-15 data strobe
CSWR_LO();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//6 above were working, testing more
//NOP();
//NOP();
//NOP();
//NOP();
//NOP();
//NOP();
//latch data with /WE - #LDSW
//PRGRW_HI();
CSWR_HI();
//return bus to default
ROMSEL_HI();
//Free data bus
//DATA_IP();
DATA16_IP();
}
/* Desc:SEGA GENESIS ROM Page Read with optional USB polling
* /ROMSEL based on romsel arg, EXP0/RESET unaffected
* if poll is true calls usbdrv.h usbPoll fuction
* this is needed to keep from timing out when double buffering usb data
* Pre: snes_init() setup of io pins
* num_bytes can't exceed 256B page boundary
* Post:address left on bus
* data bus left clear
* data buffer filled starting at first to last
* Rtn: Index of last byte read
*/
uint8_t genesis_page_rd( uint8_t *data, uint16_t addrH, uint8_t first, uint8_t len )
{
uint8_t i;
uint16_t address = first>>1; //shift because there is no A0
//address = ((addrH<<8) | first)>>1; //shift because there is no A0
address = (addrH<<7) | address; //shift because there is no A0
//set address
//ADDRH(addrH);
ADDRH(address>>8);
//set #C_CE
ROMSEL_LO();
//set #C_OE
CSRD_LO();
first = address;
//set lower address bits
ADDRL(first); //doing this prior to entry and right after latching
//gives longest delay between address out and latching data
for( i=0; i<=len; i++ ) {
//gameboy needed some extra NOPS
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//latch data high byte
data[i] = HDATA_VAL;
i++;
//latch data low byte
DATA_RD(data[i]);
//set lower address bits
//ADDRL(++first); THIS broke things, on stm adapter because macro expands it twice!
first++;
ADDRL(first);
}
//return bus to default
CSRD_HI();
ROMSEL_HI();
//return index of last byte read
return i;
}
/* Desc:SEGA GENESIS RAM Page Read with optional USB polling
* /ROMSEL based on romsel arg, EXP0/RESET unaffected
* if poll is true calls usbdrv.h usbPoll fuction
* this is needed to keep from timing out when double buffering usb data
* Pre: snes_init() setup of io pins
* num_bytes can't exceed 256B page boundary
* Post:address left on bus
* data bus left clear
* data buffer filled starting at first to last
* Rtn: Index of last byte read
*/
uint8_t genesis_ram_page_rd( uint8_t *data, uint16_t addrH, uint8_t first, uint8_t len )
{
uint8_t i;
//set address bus
ADDRH(addrH);
//set #C_CE
ROMSEL_LO();
//set #C_OE
CSRD_LO();
//set lower address bits
ADDRL(first); //doing this prior to entry and right after latching
//gives longest delay between address out and latching data
for( i=0; i<=len; i++ ) {
//gameboy needed some extra NOPS
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
NOP();
//latch data high byte
// data[i] = HDATA_VAL;
// i++;
//latch data low byte
DATA_RD(data[i]);
//set lower address bits
//ADDRL(++first); THIS broke things, on stm adapter because macro expands it twice!
first++;
ADDRL(first);
}
//return bus to default
CSRD_HI();
ROMSEL_HI();
//return index of last byte read
return i;
}
void gen_sst_flash_wr( uint16_t addr, uint16_t data )
{
uint16_t rv;
//dict.sega("GEN_SET_ADDR", 0x5555)
//dict.sega("GEN_FLASH_WR_ADDROFF", 0x00AA, 0)
gen_flash_wr(0x5555, 0x00AA);
//dict.sega("GEN_SET_ADDR", 0x2AAA)
//dict.sega("GEN_FLASH_WR_ADDROFF", 0x0055, 0)
gen_flash_wr(0x2AAA, 0x0055);
//dict.sega("GEN_SET_ADDR", 0x5555)
//dict.sega("GEN_FLASH_WR_ADDROFF", 0x00A0, 0) --write byte command
gen_flash_wr(0x5555, 0x00A0);
//dict.sega("GEN_SET_ADDR", addr)
//dict.sega("GEN_FLASH_WR_ADDROFF", value, 0) --write value
gen_flash_wr(addr, data);
do {
rv = gen_rom_rd(addr);
// usbPoll(); //orignal kazzo needs this frequently to slurp up incoming data
} while (rv != gen_rom_rd(addr));
return;
}
#endif //SEGA_CONN