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implement additional latch logic 

fixes tests 06, 07, 08, 09, 13... mostly at least
This commit is contained in:
Morilli 2025-06-22 22:35:14 +02:00
parent 6e07142d25
commit d8ae2aa805
4 changed files with 31 additions and 22 deletions
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3
bsnes/sfc/cpu/cpu.hpp
View File

@ -122,6 +122,9 @@ private:
uint2 autoJoypadPort0 = 0;
uint2 autoJoypadPort1 = 0;
bool cpuLatch = false;
bool autoJoypadLatch = false;
} status;
struct IO {

16
bsnes/sfc/cpu/io.cpp
View File

@ -130,18 +130,20 @@ auto CPU::writeCPU(uint addr, uint8 data) -> void {
//bit 0 is shared between JOYSER0 and JOYSER1:
//strobing $4016.d0 affects both controller port latches.
//$4017 bit 0 writes are ignored.
controllerPort1.device->latch(data & 1);
controllerPort2.device->latch(data & 1);
status.cpuLatch = data & 1;
controllerPort1.device->latch(status.autoJoypadLatch | status.cpuLatch);
controllerPort2.device->latch(status.autoJoypadLatch | status.cpuLatch);
return;
case 0x4200: //NMITIMEN
io.autoJoypadPoll = data & 1;
if(status.autoJoypadCounter < 2) {
if(status.autoJoypadCounter == 0) {
// allow controller latches during this time
controllerPort1.device->latch(io.autoJoypadPoll);
controllerPort2.device->latch(io.autoJoypadPoll);
}else if (!io.autoJoypadPoll) {
status.autoJoypadCounter = 33; // Disable auto-joypad read
status.autoJoypadLatch = io.autoJoypadPoll;
controllerPort1.device->latch(status.autoJoypadLatch | status.cpuLatch);
controllerPort2.device->latch(status.autoJoypadLatch | status.cpuLatch);
} else if (!io.autoJoypadPoll && status.autoJoypadCounter >= 2) {
status.autoJoypadCounter = 33;
}
nmitimenUpdate(data);

3
bsnes/sfc/cpu/serialization.cpp
View File

@ -48,6 +48,9 @@ auto CPU::serialize(serializer& s) -> void {
s.integer(status.autoJoypadPort0);
s.integer(status.autoJoypadPort1);
s.boolean(status.cpuLatch);
s.boolean(status.autoJoypadLatch);
s.integer(io.wramAddress);
s.boolean(io.hirqEnable);

31
bsnes/sfc/cpu/timing.cpp
View File

@ -214,15 +214,9 @@ auto CPU::joypadEdge() -> void {
if(status.autoJoypadCounter == 0) {
//latch controller states on the first polling cycle
controllerPort1.device->latch(io.autoJoypadPoll);
controllerPort2.device->latch(io.autoJoypadPoll);
}
if(status.autoJoypadCounter == 1) {
//release latch and begin reading on the second cycle
controllerPort1.device->latch(0);
controllerPort2.device->latch(0);
status.autoJoypadLatch = io.autoJoypadPoll;
controllerPort1.device->latch(status.autoJoypadLatch | status.cpuLatch);
controllerPort2.device->latch(status.autoJoypadLatch | status.cpuLatch);
if(io.autoJoypadPoll) {
//shift registers are cleared to zero at start of auto-joypad polling
io.joy1 = 0;
@ -232,13 +226,20 @@ auto CPU::joypadEdge() -> void {
}
}
if(status.autoJoypadCounter >= 2) {
if (!io.autoJoypadPoll) {
// if auto-joypad polling is disabled at this point skip the rest of the polling
status.autoJoypadCounter = 33;
return;
}
if(status.autoJoypadCounter == 1) {
//release latch and begin reading on the second cycle
status.autoJoypadLatch = 0;
controllerPort1.device->latch(status.autoJoypadLatch | status.cpuLatch);
controllerPort2.device->latch(status.autoJoypadLatch | status.cpuLatch);
}
if(status.autoJoypadCounter != 1 && !io.autoJoypadPoll) {
// if auto-joypad polling is disabled at this point skip the rest of the polling
status.autoJoypadCounter = 33;
return;
}
if(status.autoJoypadCounter >= 2) {
//sixteen bits are shifted into joy{1-4}, one bit per 256 clocks
//the bits are read on one 128-clock cycle and written on the next
if ((status.autoJoypadCounter & 1) == 0) {