Omron CS1G/H-CPUxxH Instructions Manual page 274

Comparison Instructions
Description CMP(020) compares the unsigned binary data in S
result to Arithmetic Flags (the Greater Than, Greater Than or Equal, Equal,
Less Than or Equal, Less Than, and Not Equal Flags) in the Auxiliary Area.
Condition Flag Status
The following table shows the status of the Arithmetic Flags after execution of
CMP(020). (A status of "---" indicates that the Flag may be ON or OFF.)
CMP(020)
Result
>
S > S ON ON
1 2
S = S OFF ON
1 2
S < S OFF OFF
1 2
Using CMP(020) Results in the Program
When CMP(020) is executed, the result is reflected in the Arithmetic Flags.
Control the desired output or right-hand instruction with a branch from the
same input condition that controls CMP(020), as shown in the following dia-
gram. In this case, the Equals Flag and output A will be turned ON when S
S .
2
Correct Use of CMP(020)
Using CMP(020) Results in the Program
Do not program another instruction between CMP(020) and the instruction
controlled by the Arithmetic Flag because the other instruction might change
the status of the Arithmetic Flag. In this case, the results of instruction B might
change the results of CMP(020).
Incorrect Use of CMP(020)
Unsigned binary
comparison
Arithmetic Flags
(>, >=, =, <=, <, <>)
Flag status
> = = < =
OFF OFF
ON ON
OFF ON
Arithmetic Flag
(Example: Equal Flag)
Arithmetic Flag
(Example: Equal Flag)
Section 3-7
and S and outputs the
1 2
< < >
OFF ON
OFF OFF
ON ON
CMP
S1
S2
A
CMP
S1
S2
Instruction
B
A
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1