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SBC A,n     Subtract Through Carry     Rabbit 2000/3000/4000/5000 Instruction

Opcode	Instruction	Operation
DE n	SBC A,n	A = A - n - CF

Clocks	8-Bit Access	16-Bit Unaligned	16-Bit Aligned
Rabbit 2000/3000/4000	4	n/a	n/a
Rabbit 5000	4	4	2

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

Description

Subtracts the C flag and the 8-bit constant n from A.The difference is stored in A. These operations output an inverted carry:

• The C flag is set if A is less than the data being subtracted from it.

• The C flag is cleared if A is greater than the data being subtracted from it.

• The C flag is unchanged if A is equal to the data being subtracted from it.

The Rabbit 4000/5000 assemblers view "SBC A,n" and "SBC n" as equivalent instructions. In the latter case, A is used even though it is not explicitly stated.