Zilog Z08470 User Manual
Page 186
Z80 Instruction Set
UM008007-0715
174
Z80 CPU
User Manual
NEG
Operation
A ← 0 – A
Op Code
NEG
Operands
None.
Description
The contents of the Accumulator are negated (two’s complement). This method is the
same as subtracting the contents of the Accumulator from zero.
The
80h
address remains unchanged.
Condition Bits Affected
S is set if result is negative; otherwise, it is reset.
Z is set if result is 0; otherwise, it is reset.
H is set if borrow from bit 4; otherwise, it is reset.
P/V is set if Accumulator was
80h
before operation; otherwise, it is reset.
N is set.
C is set if Accumulator was not
00h
before operation; otherwise, it is reset.
M Cycles
T States
4 MHz E.T.
2
8 (4, 4)
2.00
1
1
0
0
1
1
1
1
ED
0
1
0
0
0
1
0
0
44
Note: