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