srctree

Johan Norberg parent 92428bba 1378f771
Clear write toggle when reading ppu status register

* Documented here: https://wiki.nesdev.org/w/index.php?title=PPU_registers#Notes
core/src/ppu.cpp added: 6, removed: 3, total 3
@@ -104,6 +104,7 @@ uint8_t Ppu::read_byte(uint16_t addr) {
 
if (addr == kPpuStatus) {
byte = registers_->status;
registers_->write_toggle = false;
clear_vblank_flag();
} else if (addr == kOamData) {
byte = oam_data_[registers_->oamaddr];
 
core/test/src/test_ppu.cpp added: 6, removed: 3, total 3
@@ -46,8 +46,10 @@ TEST_F(PpuTest, writes_to_mmu_for_unhandled_address) {
ppu->write_byte(0x1000, 0x45);
}
 
TEST_F(PpuTest, read_status_register) {
TEST_F(PpuTest, read_status_register_clears_write_toggle) {
registers.status = 0x25;
registers.write_toggle = true;
expected.write_toggle = false;
 
const uint8_t status = ppu->read_byte(0x2002);