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Correct address calculation for absolute indirect and absolute indirect X modes.

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This commit is contained in:
Radosław Kujawa 2017-01-28 00:10:22 +01:00
parent 8d2d694158
commit 735c3677ce
1 changed files with 10 additions and 5 deletions
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15
src/emulation.c
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@ -156,17 +156,22 @@ emul_iny(rk65c02emu_t *e, void *id, instruction_t *i)
void
emul_jmp(rk65c02emu_t *e, void *id, instruction_t *i)
{
uint16_t target;//, iaddr;
uint16_t target, iaddr;
switch (((instrdef_t *)id)->mode) {
case ABSOLUTE:
target = i->op1 + (i->op2 << 8);
break;
case IABSOLUTE:
target = bus_read_1(e->bus, i->op1);
target |= (bus_read_1(e->bus, i->op2) << 8);
// target = bus_read_1(e->bus, indirect);
// target |= bus_read_1(e->bus, indirect + 1);
iaddr = i->op1 + (i->op2 << 8);
target = bus_read_1(e->bus, iaddr);
target |= bus_read_1(e->bus, iaddr+1) << 8;
break;
case IABSOLUTEX:
iaddr = i->op1 + (i->op2 << 8) + e->regs.X;
target = bus_read_1(e->bus, iaddr);
target |= bus_read_1(e->bus, iaddr + 1) << 8;
break;
default:
assert(false); /* should never happen, lol */
break;