static inline void IRQ()
{
Stack_Push_Address(CPU.PC);
Stack_Push(Status_Read());
CPU.I = 1;
CPU.PC = (Memory_CPU_Read(0xFFFF) << 8) | Memory_CPU_Read(0xFFFE);
}
void T1_Main(void) {
static uint8 state = 0, timer, band, send, bits, band_request, band_request_timer;
static uint16 tune_timer;
if (tune_timer) {
tune_timer--;
if (!tune_timer) {
Control_Write(Control_Read() & ~CONTROL_ATU_1);
}
}
if (band_request_timer) band_request_timer--;
else if (T1_Band_Number != band) {
band_request = 1;
band_request_timer = 200;
}
switch(state) {
case 0: // idle
if (Status_Read() & STATUS_ATU_0) timer++;
else {
if (timer >= 85 && timer <= 115) {
state = 1;
timer = 20;
send = band = T1_Band_Number;
bits = 4;
Control_Write(Control_Read() & ~CONTROL_ATU_0 | CONTROL_ATU_0_OE);
}
else {
timer = 0;
if (band_request || T1_Tune_Request) {
Control_Write(Control_Read() | CONTROL_ATU_1);
if (T1_Tune_Request) tune_timer = 1000;
else tune_timer = 10;
band_request = T1_Tune_Request = 0;
}
}
}
break;
case 1: // data low
timer--;
if (!timer) {
if (bits) {
Control_Write(Control_Read() | CONTROL_ATU_0);
if (send & 0x08) timer = 8;
else timer = 3;
send <<= 1;
bits--;
state = 2;
} else {
Control_Write(Control_Read() & ~(CONTROL_ATU_0 | CONTROL_ATU_0_OE));
state = 0;
}
}
break;
case 2: // data high
timer--;
if (!timer) {
if (bits) timer = 3;
else timer = 10;
Control_Write(Control_Read() & ~CONTROL_ATU_0);
state = 1;
}
break;
}
}