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Emulator: Implement AND opcodes

master
Riyyi 2 years ago
parent
commit
462fa09a00
  1. 55
      src/cpu.cpp
  2. 1
      src/cpu.h

55
src/cpu.cpp

@ -175,6 +175,14 @@ void CPU::update()
case 0x7d: ldr8(); break;
case 0x7e: ldr8(); break;
case 0x7f: ldr8(); break;
case 0xa0: and8(); break;
case 0xa1: and8(); break;
case 0xa2: and8(); break;
case 0xa3: and8(); break;
case 0xa4: and8(); break;
case 0xa5: and8(); break;
case 0xa6: and8(); break;
case 0xa7: and8(); break;
case 0xa8: xor8(); break;
case 0xaf: xor8(); break;
case 0xb8: cp(); break;
@ -190,6 +198,7 @@ void CPU::update()
case 0xcd: call(); break;
case 0xe0: ldffi8(); break;
case 0xe2: ldr8(); break;
case 0xe6: and8(); break;
case 0xe8: adds8(); break;
case 0xea: ldr8(); break;
case 0xf0: ldffi8(); break;
@ -233,6 +242,52 @@ void CPU::addi8()
}
}
void CPU::and8()
{
auto bitwise_and = [this](uint32_t byte) {
// AND r8, flags: Z 0 1 0
m_wait_cycles += 4;
// Set flags
m_nf = 0;
m_hf = 1;
m_cf = 0;
// Bitwise AND between the value in r8 and A
m_a = m_a & byte;
// Zero flag
m_zf = m_a == 0;
};
uint8_t opcode = pcRead();
switch (opcode) {
case 0xa0: /* AND B */ bitwise_and(m_b); break;
case 0xa1: /* AND C */ bitwise_and(m_c); break;
case 0xa2: /* AND D */ bitwise_and(m_d); break;
case 0xa3: /* AND E */ bitwise_and(m_e); break;
case 0xa4: /* AND H */ bitwise_and(m_h); break;
case 0xa5: /* AND L */ bitwise_and(m_l); break;
case 0xa6: /* AND (HL) */ {
m_wait_cycles += 4; // + 4 = 8 total
// Bitwise AND between the byte pointed to by HL and A
bitwise_and(read(hl()));
break;
}
case 0xa7: /* AND A */ bitwise_and(m_a); break;
case 0xe6: /* AND i8 */ {
m_wait_cycles += 4; // + 4 = 8 total
// Bitwise AND between the value in i8 and A
bitwise_and(pcRead());
break;
}
default:
VERIFY_NOT_REACHED();
}
}
void CPU::dec8()
{
auto decrement = [this](uint32_t& reg) -> void {

1
src/cpu.h

@ -29,6 +29,7 @@ public:
// 8-bit
void addi8();
void and8();
void dec8();
void xor8();

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