Rabbit 2000 - Page 98

94 Rabbit 2000/3000 Microprocessor
Description
• SBC A,n: Subtracts the Carry Flag, CF, and the 8-bit constant n from the data in the Accumu-
lator.
• SBC A,r: Subtracts the Carry Flag, CF, and the data in the register r (any of the registers A,
B, C, D, E, H, or L) from the data in the Accumulator.
The difference is stored in the Accumulator.
These operations output an inverted carry:
• The Carry Flag is set if the Accumulator is less than the data being subtracted from it.
• The Carry Flag is cleared if the Accumulator is greater than the data being subtracted from it.
SBC A,n
SBC A,r
Opcode Instruction Clocks Operation
DE n SBC A,n 4 (2,2) A=A-n -CF
——
9F
98
99
9A
9B
9C
9D
SBC A,r
SBC A,A
SBC A,B
SBC A,C
SBC A,D
SBC A,E
SBC A,H
SBC A,L
2
2
2
2
2
2
2
2
A=A-r -CF
A=A-A-CF
A=A-B-CF
A=A-C-CF
A=A-D-CF
A=A-E-CF
A=A-H-CF
A=A-L-CF
Flags ALTD I/O
S Z L/V C F R SP S D
• • V • • •