Zilog Z86193 - Manual (Page 247)

Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
240
Swap Nibbles
Syntax
SWAP dst
Instruction Format
Operation
dst(7-4)
↔
dst(3-0)
The contents of the lower four bits and upper four bits of the destination operand are
swapped.
Address modes R or IR can be used to specify a 4-bit Working Register. In this format, des-
tination Working Register operand is specified by adding
1110b
(
Eh
) to the high nibble of
the operand. For example, if Working Register
R12 (CH)
is the destination operand, then
ECh
is used as the destination operand in the Op Code.
Example 1
If Register
BCh
contains
B3h
(10110011B), the statement:
SWAP B3h
Op Code: F0 B3
leaves the value
3Bh
(00111011B) in Register
BCh
. The Z and S Flags are cleared.
Cycles
OPC
(Hex)
Address Mode
dst
OPC dst
6 F0 R
6 F1 IR
Flag Description
C Unaffected
Z Set if the result is zero; cleared otherwise.
S Set if the result bit 7 is set; cleared otherwise.
V Undefined
D Unaffected
H Unaffected
E dst
Note: