vin/emu_nes
1
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

add jsr, rti, rts

Browse Source
This commit is contained in:
Vineet K 2024-06-10 23:25:49 +05:30
parent 3412a03a5e
commit a3189d90af
1 changed files with 16 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
cpu.c
View File

@ -407,15 +407,23 @@ iny(uint8_t arg)
}
static void
jmp(uint8_t arg)
jmp(uint16_t arg)
{
regs.pc = arg;
}
static void
jsr(uint8_t arg)
jsr(uint16_t arg)
{
/* TODO: complete this */
uint16_t tmp = regs.pc + 2;
/*
* first push high-byte of return address then low-byte
* https://www.masswerk.at/6502/6502_instruction_set.html
*/
PUSH((tmp & 0xFF00) >> 8);
PUSH(tmp & 0xFF);
regs.pc = arg;
}
static void
@ -547,13 +555,14 @@ ror(uint8_t arg)
static void
rti(uint8_t arg)
{
/* TODO: complete this */
plp();
regs.pc = PULL();
}
static void
rts(uint8_t arg)
rts(void)
{
/* TODO: complete this */
regs.pc = PULL() + 1;
}
static void
@ -1186,7 +1195,7 @@ interpret(void)
cycles += 6;
break;
case 0x60:
rts(opcode_arg(AM_ACC));
rts();
cycles += 6;
break;
case 0xe9: