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30Mar98@15:00h
Semiconductor Group
55
Version 1.2, 12.97
C166 Family Instruction Set
Instruction Description
CMPB
Integer Compare
CMPB
Syntax
CMPB
op1, op2
Operation
(op1)
⇔
(op2)
Data Types
BYTE
Description
The source operand specified by op1 is compared to the source operand
specified by op2 by performing a 2’s complement binary subtraction of
op2 from op1. The flags are set according to the rules of subtraction. The
operands remain unchanged.
E Set if the value of op2 represents the lowest possible negative number.
Cleared otherwise. Used to signal the end of a table.
Z Set if result equals zero. Cleared otherwise.
V Set if an arithmetic underflow occurred, ie. the result cannot be repre-
sented in the specified data type. Cleared otherwise.
C Set if a borrow is generated. Cleared otherwise.
N Set if the most significant bit of the result is set. Cleared otherwise.
Addressing Modes
Mnemonic
Format
Bytes
CMPB
Rb
n
, Rb
m
41 nm
2
CMPB
Rb
n
, [Rw
i
]
49 n:10ii
2
CMPB
Rb
n
, [Rw
i
+]
49 n:11ii
2
CMPB
Rb
n
, #data3
49 n:0###
2
CMPB
reg, #data16
47 RR ## xx
4
CMPB
reg, mem
43 RR MM MM
4
Condition Flags
E
Z
V
C
N
*
*
*
S
*