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50 lines
1.2 KiB
C++
50 lines
1.2 KiB
C++
//
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// Created by anonymus-raccoon on 2/10/20.
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//
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#include "../CPU.hpp"
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namespace ComSquare::CPU
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{
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unsigned CPU::RESB()
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{
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this->_registers.p.i = true;
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this->_registers.p.d = false;
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this->_isEmulationMode = true;
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this->_registers.p.m = true;
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this->_registers.p.x_b = true;
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this->_registers.dbr = 0x00;
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this->_registers.pbr = 0x00;
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this->_registers.d = 0x0000;
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this->_registers.sh = 0x01; // the low bit of the stack pointer is undefined on reset.
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this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.reset;
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return 0;
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}
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unsigned CPU::BRK()
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{
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// TODO rework this. The PC should be pushed to the stack.
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// Info here: http://softpixel.com/~cwright/sianse/docs/65816NFO.HTM at BRK Software Break
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this->_registers.pc += 2;
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this->_registers.p.i = true;
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if (this->_isEmulationMode)
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this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.brk;
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else
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this->_registers.pc = this->_cartridgeHeader.nativeInterrupts.brk;
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this->_registers.p.d = false;
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return !this->_isEmulationMode;
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}
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unsigned CPU::RTI()
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{
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this->_registers.p.flags = this->pop();
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this->_registers.pc = this->pop16();
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if (!this->_isEmulationMode) {
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this->_registers.pbr = this->pop16();
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return 1;
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}
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return 0;
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}
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} |