diff options
Diffstat (limited to 'assembler/register.s')
| -rw-r--r-- | assembler/register.s | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/assembler/register.s b/assembler/register.s new file mode 100644 index 0000000..9fbc76c --- /dev/null +++ b/assembler/register.s @@ -0,0 +1,39 @@ +register: + PUSH {LR} +10: + BL get_char + MOVS R1, 'R + CMPS R0, R1 + BNE 10b +20: + BL get_char + MOVS R1, '0 + CMPS R0, R1 + BLO 20b + MOVS R1, '9 + CMPS R0, R1 + BHI 20b + MOVS R1, '1 + CMPS R0, R1 + BNE 30f +50: + BL get_char + BEQ 60f + MOVS R1, '0 + CMPS R0, R1 + BLO 50b + MOVS R1, '5 + CMPS R0, R1 + BHI 50b + ADDS R0, 10 +30: + SUBS R0, '0 + MOVS R4, 0 + ORRS R4, R0 +40: + BL get_char + BNE 40b + POP {PC} +60: + MOVS R4, 1 + POP {PC} |