analog/v2-analog-rev1/z80/businterface.c
2023-01-29 10:50:12 -05:00

62 lines
1.5 KiB
C

#include <string.h>
#include <hardware/pio.h>
#include "common/config.h"
#include "common/buffers.h"
#include "abus.pio.h"
#include "z80/businterface.h"
#include "z80/z80buf.h"
volatile uint8_t *pcpi_reg = apple_memory + 0xC0C0;
static inline void __time_critical_func(pcpi_read)(uint32_t address) {
switch(address & 0x7) {
case 0: // Read Data from Z80
clr_6502_stat;
break;
case 5: // Z80 Reset
z80_res = 1;
break;
case 6: // Z80 INT
//z80_irq = 1;
break;
case 7: // Z80 NMI
z80_nmi = 1;
break;
}
}
static inline void __time_critical_func(pcpi_write)(uint32_t address, uint32_t value) {
switch(address & 0x7) {
case 0:
case 2:
case 3:
case 4:
break;
case 1: // Write Data to Z80
pcpi_reg[1] = value & 0xff;
set_z80_stat;
break;
case 5:
case 6:
case 7:
pcpi_read(address);
break;
}
}
void __time_critical_func(z80_businterface)(uint32_t address, uint32_t value) {
pcpi_reg = apple_memory + (0xC080 | (cardslot << 4));
// Shadow parts of the Apple's memory by observing the bus write cycles
if(CARD_SELECT) {
if(CARD_DEVSEL) {
if((value & (1u << CONFIG_PIN_APPLEBUS_RW-CONFIG_PIN_APPLEBUS_DATA_BASE)) == 0) {
pcpi_write(address, value);
} else {
pcpi_read(address);
}
}
}
}