<< Previous | Next >>

> SBC A,r Subtract with Carry Rabbit 4000 Instruction

> Opcode | Instruction | Clocks | Operation
> -- | SBC A,r | 4 (2,2) | A = A - r - CF
> 7F 9F | SBC A,A | 4 (2,2) | A = A - A - CF
> 7F 98 | SBC A,B | 4 (2,2) | A = A - B - CF
> 7F 99 | SBC A,C | 4 (2,2) | A = A - C - CF
> 7F 9A | SBC A,D | 4 (2,2) | A = A - D - CF
> 7F 9B | SBC A,E | 4 (2,2) | A = A - E - CF
> 7F 9C | SBC A,H | 4 (2,2) | A = A - H - CF
> 7F 9D | SBC A,L | 4 (2,2) | A = A - L - CF

> Flags | ALTD | IOI/IOE
> S | Z | L/V | C | F | R | SP | S | D
> · | · | V | · | · | · |  |  |

> #### Description

> Subtracts the C flag and the data in r (one of A, B, C, D, E, H or L) from A. The result is stored in A.

> The Rabbit 4000 assembler views "SBC A,r" and "SBC r" as equivalent instructions. In the latter case, A is used even though it is not explicitly stated.

> The opcodes for these instructions are different than the same instructions in the Rabbit 2000, 3000 and 3000A.

<< Previous | Next >>