Apple-2-SW
/
Applerm-II
mirror of https://github.com/toyoshim/Applerm-II.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Fix branch operation bugs 

- address calculation on not taken
 - use macro to implement each branch operation
This commit is contained in:
Takashi Toyoshima 2014-12-07 14:05:38 +09:00
parent 8d94c76d47
commit ff1f7b8b2f
2 changed files with 31 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
6502.S
View File

@ -401,8 +401,27 @@
1:
.endm
.macro _bxc reg
adds PC, PC, #1
movs r0, #\reg
tst SR, r0
bne 1f
_bxx
1:
.endm
.macro _bxs reg
adds PC, PC, #1
movs r0, #\reg
tst SR, r0
beq 1f
_bxx
1:
.endm
.macro _bxx
_fromImmb
mov r0, PC
_ldb
sxtb r0, r0
add PC, PC, r0
.endm
@ -807,11 +826,7 @@ op0e: // ASL - Absolute
_decode
op10: // BPL (N==0)
movs r0, #FLAG_N
tst SR, r0
bne 1f
_bxx
1:
_bxc FLAG_N
_decode
op11: // ORA - (Indirect), Y
@ -913,11 +928,7 @@ op2e: // ROL - Absolute
_decode
op30: // BMI (N==1)
movs r0, #FLAG_N
tst SR, r0
beq 1f
_bxx
1:
_bxs FLAG_N
_decode
op31: // AND - (Indirect), Y
@ -1010,11 +1021,7 @@ op4e: // LSR - Absolute
_decode
op50: // BVC (V==0)
movs r0, #FLAG_V
tst SR, r0
bne 1f
_bxx
1:
_bxc FLAG_V
_decode
op51: // EOR - (Indirect), Y
@ -1111,11 +1118,7 @@ op6e: // ROR - Absolute
_decode
op70: // BVS (V==1)
movs r0, #FLAG_V
tst SR, r0
beq 1f
_bxx
1:
_bxs FLAG_V
_decode
op71: // ADC - (Indirect), Y
@ -1199,11 +1202,7 @@ op8e: // STX - Absolute
_decode
op90: // BCC (C==0)
movs r0, #FLAG_C
tst SR, r0
bne 1f
_bxx
1:
_bxc FLAG_C
_decode
op91: // STA - (Indirect), Y
@ -1308,11 +1307,7 @@ opae: // LDX - Absolute
_decode
opb0: // BCS (C==1)
movs r0, #FLAG_C
tst SR, r0
beq 1f
_bxx
1:
_bxs FLAG_C
_decode
opb1: // LDA - (Indirect), Y
@ -1423,11 +1418,7 @@ opce: // DEC - Absolute
_decode
opd0: // BNE (Z==0)
movs r0, #FLAG_Z
tst SR, r0
bne 1f
_bxx
1:
_bxc FLAG_Z
_decode
opd1: // CMP - (Indirect), Y
@ -1520,11 +1511,7 @@ opee: // INC - Absolute
_decode
opf0: // BEQ (Z==1)
movs r0, #FLAG_Z
tst SR, r0
beq 1f
_bxx
1:
_bxs FLAG_Z
_decode
opf1: // SBC - (Indirect), Y

3
test.c
View File

@ -14,15 +14,18 @@ void cpu6502_dump(
"NV-B_DIZC=%d%d-%d_%d%d%d%d\n",
pc, a, x, y, sp, (sr >> 7) & 1, (sr >> 6) & 1, (sr >> 4) & 1,
(sr >> 3) & 1, (sr >> 2) & 1, (sr >> 1) & 1, sr & 1);
fflush(stdout);
}
uint8_t cpu6502_load(uint16_t addr) {
printf("load $%04x => $%02x\n", addr, mem[addr]);
fflush(stdout);
return mem[addr];
}
void cpu6502_store(uint16_t addr, uint8_t data) {
printf("store $%04x <= $%02x\n", addr, data);
fflush(stdout);
mem[addr] = data;
}