153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
#include "sega.h"
|
|
|
|
//only need this file if connector is present on the device
|
|
#ifdef SEGA_CONN
|
|
|
|
//=================================================================================================
|
|
//
|
|
// 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 SEGA_WR:
|
|
sega_wr( operand, miscdata );
|
|
break;
|
|
|
|
case 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();
|
|
}
|
|
break;
|
|
|
|
//8bit return values:
|
|
case SEGA_RD:
|
|
rdata[RD_LEN] = BYTE_LEN;
|
|
rdata[RD0] = sega_rd( operand );
|
|
break;
|
|
default:
|
|
//macro doesn't exist
|
|
return ERR_UNKN_SEGA_OPCODE;
|
|
}
|
|
|
|
return SUCCESS;
|
|
|
|
}
|
|
|
|
uint8_t sega_rd( uint16_t addr )
|
|
{
|
|
return 0xAA;
|
|
}
|
|
|
|
|
|
void sega_wr( uint16_t addr, uint8_t data )
|
|
{
|
|
return;
|
|
}
|
|
|
|
|
|
/* Desc:SNES 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;
|
|
}
|
|
|
|
|
|
#endif //SEGA_CONN
|