Zilog Z80380 - Manual (Page 193)

5-159
Z380 ™
U SER ' S M ANUAL Z ILOG
DC-8297-03
SBC
SUBTRACT WITH CARRY (BYTE)
SBC A,src src = R, RX, IM, IR, X
Operation: A
←
A - src - C
The source operand together with the Carry flag is subtracted from the accumulator and the
difference is stored in the accumulator. The contents of the source are unaffected. Two's
complement subtraction is performed.
Flags: S: Set if the result is negative; cleared otherwise
Z: Set if the result is zero; cleared otherwise
H: Set if there is a borrow from bit 4 of the result; cleared otherwise
V: Set if arithmetic overflow occurs, that is, if the operands are of different signs and the
result is of the same sign as the source; cleared otherwise
N: Set
C: Set if there is a borrow from the most significant bit of the result; cleared otherwise
Addressing Execute
Mode Syntax Instruction Format Time Note
R: SBC A,R 10011-r- 2
RX: SBC A,RX 11y11101 1001110w 2
IM: SBC A,n 11011110 ——n— 2
IR: SBC A,(HL) 10011110 2+r
X: SBC A,(XY+d) 11y11101 10011110 ——d— 4+r I
Field Encodings: r: per convention
y: 0 for IX, 1 for IY
w: 0 for high byte, 1 for low byte