91 lines
2.2 KiB
C++
Executable File
91 lines
2.2 KiB
C++
Executable File
#ifdef SCPU_CPP
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#include "opfn.cpp"
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void sCPU::enter() {
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initialize:
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//initial latch values for $213c/$213d
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//[x]0035 : [y]0000 (53.0 -> 212) [lda $2137]
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//[x]0038 : [y]0000 (56.5 -> 226) [nop : lda $2137]
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add_clocks(186);
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loop:
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if(status.interrupt_pending) {
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status.interrupt_pending = false;
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if(status.nmi_pending) {
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status.nmi_pending = false;
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status.interrupt_vector = (regs.e == false ? 0xffea : 0xfffa);
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} else if(status.irq_pending) {
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status.irq_pending = false;
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status.interrupt_vector = (regs.e == false ? 0xffee : 0xfffe);
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}
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op_irq();
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}
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tracer.trace_cpuop(); //traces CPU opcode (only if tracer is enabled)
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status.in_opcode = true;
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switch(op_readpc()) {
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#include "op_read.cpp"
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#include "op_write.cpp"
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#include "op_rmw.cpp"
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#include "op_pc.cpp"
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#include "op_misc.cpp"
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}
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status.in_opcode = false;
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goto loop;
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}
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void sCPU::op_irq() {
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op_read(regs.pc.d);
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op_io();
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if(!regs.e) op_writestack(regs.pc.b);
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op_writestack(regs.pc.h);
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op_writestack(regs.pc.l);
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op_writestack(regs.e ? (regs.p & ~0x10) : regs.p);
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rd.l = op_read(status.interrupt_vector + 0);
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regs.pc.b = 0x00;
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regs.p.i = 1;
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regs.p.d = 0;
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rd.h = op_read(status.interrupt_vector + 1);
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regs.pc.w = rd.w;
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}
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//immediate, 2-cycle opcodes with I/O cycle will become bus read
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//when an IRQ is to be triggered immediately after opcode completion
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//this affects the following opcodes:
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// clc, cld, cli, clv, sec, sed, sei,
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// tax, tay, txa, txy, tya, tyx,
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// tcd, tcs, tdc, tsc, tsx, txs,
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// inc, inx, iny, dec, dex, dey,
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// asl, lsr, rol, ror, nop, xce.
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alwaysinline void sCPU::op_io_irq() {
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if(status.interrupt_pending) {
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//IRQ pending, modify I/O cycle to bus read cycle, do not increment PC
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op_read(regs.pc.d);
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} else {
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op_io();
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}
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}
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alwaysinline void sCPU::op_io_cond2() {
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if(regs.d.l != 0x00) {
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op_io();
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}
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}
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alwaysinline void sCPU::op_io_cond4(uint16 x, uint16 y) {
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if(!regs.p.x || (x & 0xff00) != (y & 0xff00)) {
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op_io();
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}
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}
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alwaysinline void sCPU::op_io_cond6(uint16 addr) {
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if(regs.e && (regs.pc.w & 0xff00) != (addr & 0xff00)) {
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op_io();
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}
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}
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#endif
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