| 指令 | 說明 | 週期 |
| ADD A,Rn | A←A+Rn | 12 |
| ADD A,direct | A←A+direct | 12 |
| ADD A,@Ri | A←A+Ri | 12 |
| ADD A,#data | A←A+data | 12 |
| ADDC A,Rn | A←A+Rn+C | 12 |
| ADDC A,direct | A←A+direct+C | 12 |
| ADDC A,@Ri | A←A+Ri+C | 12 |
| ADDC A,#data | A←A+data+C | 12 |
| SUBB A,Rn | A←A-Rn-C | 12 |
| SUBB A,direct | A←A-direct-C | 12 |
| SUBB A,@Ri | A←A-Ri-C | 12 |
| SUBB A,#data | A←A-data-C | 12 |
| INC A | A←A+1 | 12 |
| INC Rn | Rn←Rn+1 | 12 |
| INC direct | direct←direct+1 | 12 |
| INC @Ri | @Ri←@Ri+1 | 12 |
| INC DPTR | DPTR←DPTR+1 | 12 |
| DEC A | A←A-1 | 12 |
| DEC Rn | Rn←Rn-1 | 12 |
| DEC direct | direct←direct-1 | 12 |
| DEC @Ri | @Ri←@Ri-1 | 12 |
| MUL AB | 兩個無符號的8位元資料相乘，其中高階8位元放入B暫存器，低階8位元則放入累積器ACC | 24 |
| DIV AB | 兩個無符號的8位元資料相除，把ACC值除以B暫存器值，商數放回ACC，餘數放在B | 48 |
| DA A | 累加器作十進制調整 | 48 |