mirror of
https://github.com/zoriya/ComSquare.git
synced 2026-06-13 06:16:36 +00:00
Zoe Roux
77 lines
2.7 KiB
C++
77 lines
2.7 KiB
C++
//
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// Created by Melefo on 25/02/2020.
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//
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#include "APU/APU.hpp"
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namespace ComSquare::APU
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{
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int APU::INCW(uint24_t addr)
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{
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uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
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uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr)) + 1u;
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this->_internalWrite(addr, value);
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this->_internalWrite(addr2, value >> 8u);
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this->_internalRegisters.n = value & 0x8000u;
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this->_internalRegisters.z = !value;
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return 6;
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}
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int APU::DECW(uint24_t addr)
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{
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uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
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uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr)) - 1u;
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this->_internalWrite(addr, value);
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this->_internalWrite(addr2, value >> 8u);
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this->_internalRegisters.n = value & 0x8000u;
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this->_internalRegisters.z = !value;
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return 6;
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}
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int APU::ADDW(uint24_t addr)
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{
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uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
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uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr));
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uint24_t result = this->_internalRegisters.ya + value;
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this->_internalRegisters.v = (~(this->_internalRegisters.ya ^ value) & (this->_internalRegisters.ya ^ result)) & 0x8000u;
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this->_internalRegisters.c = result > 0xFFFFu;
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this->_internalRegisters.h = ((this->_internalRegisters.ya & 0x0FFFu) + (value & 0x0FFFu)) > 0x0FFFu;
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this->_internalRegisters.z = !result;
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this->_internalRegisters.n = result & 0x8000u;
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this->_internalRegisters.ya = result;
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return 5;
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}
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int APU::SUBW(uint24_t addr)
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{
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uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
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uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr));
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uint24_t result = this->_internalRegisters.ya - value;
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uint16_t tmp = ((this->_internalRegisters.ya & 0x0F00u) - (value & 0x0F00u)) >> 8u;
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if ((this->_internalRegisters.ya & 0x00FFu) < (value & 0x00FFu))
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tmp--;
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this->_internalRegisters.v = ((this->_internalRegisters.ya ^ value) & (this->_internalRegisters.ya ^ result)) & 0x8000u;
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this->_internalRegisters.c = result <= 0xFFFFu;
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this->_internalRegisters.h = tmp <= 0x000F;
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this->_internalRegisters.z = !result;
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this->_internalRegisters.n = result & 0x8000u;
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this->_internalRegisters.ya = result;
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return 5;
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}
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int APU::CMPW(uint24_t addr)
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{
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uint24_t addr2 = addr + 1 + (this->_internalRegisters.p ? 0x0100 : 0);
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uint16_t value = ((this->_internalRead(addr2) << 8u) | this->_internalRead(addr));
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uint24_t result = this->_internalRegisters.ya - value;
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this->_internalRegisters.z = !result;
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this->_internalRegisters.n = result & 0x8000u;
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this->_internalRegisters.c = this->_internalRegisters.ya >= value;
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return 4;
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}
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} |