Zilog Z08470 User Manual
Page 164
Z80 Instruction Set
UM008007-0715
152
Z80 CPU
User Manual
r identifies registers B, C, D, E, H, L, or A assembled as follows in the object code field:
Description
The s operand is subtracted from the contents of the Accumulator, and the result is stored
in the Accumulator.
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 overflow; otherwise, it is reset.
N is set.
C is set if borrow; otherwise, it is reset.
Example
If the Accumulator contents are
29h
, and the D Register contains
11h
, then upon the exe-
cution of a SUB D instruction, the Accumulator contains
18h
.
Register
r
B
000
C
001
D
010
E
011
H
100
L
101
A
111
Instruction
M Cycle
T States
4 MHz E.T.
SUB r
1
4
1.00
SUB n
2
7 (4, 3)
1.75
SUB (HL)
2
7 (4, 3)
1.75
SUB (IX+d)
5
19 (4, 4, 3, 5, 3)
4.75
SUB (lY+d)
5
19 (4, 4, 3, 5, 3)
4.75