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Finishing Program Flow Operations

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This commit is contained in:
Melefo
2020-02-24 19:06:35 +01:00
parent 92d8e97fa5
commit e9a7b9e8d7
7 changed files with 278 additions and 41 deletions
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59
sources/APU/Instructions/ProgramFlow.cpp
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@@ -8,7 +8,7 @@ namespace ComSquare::APU
{
int APU::BRA()
{
int8_t offset = this->_internalRead(this->_internalRegisters.pc++);
int8_t offset = this->_getDirectValue();
this->_internalRegisters.pc += offset;
return 4;
@@ -77,4 +77,61 @@ namespace ComSquare::APU
this->BRA();
return 4;
}
int APU::BBS(uint24_t addr, uint8_t bit)
{
uint8_t data = this->_internalRead(addr);
if (!(data & (1u << bit)))
return 5;
this->BRA();
return 7;
}
int APU::BBC(uint24_t addr, uint8_t bit)
{
uint8_t data = this->_internalRead(addr);
if (data & (1u << bit))
return 5;
this->BRA();
return 7;
}
int APU::CBNE(uint24_t addr, bool by_x)
{
uint8_t data = this->_internalRead(addr);
if (this->_internalRegisters.a == data)
return 5 + by_x;
this->BRA();
return 7 + by_x;
}
int APU::DBNZ(bool direct_addr)
{
uint8_t data;
if (direct_addr) {
uint24_t addr = this->_getDirectAddr();
data = this->_internalRead(addr);
this->_internalWrite(addr, --data);
}
else
data = --this->_internalRegisters.y;
if (!data)
return 4 + direct_addr;
this->BRA();
return 6 + direct_addr;
}
int APU::JMP(uint24_t addr, bool by_x)
{
this->_internalRegisters.pc = addr;
if (by_x)
return 6;
else
return 3;
}
}