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Individual Instruction Descriptions
4-93Assembly Language Instructions
4.14.11 CMPB Compare Two Bytes
Syntax
[label] name src, src1 Clock, clk Word, w With RPT, clk Class
CMPB An, imm8 1 1 N/R 2a
CMPB Rx, imm8 1 1 N/R 4b
Execution status flags set by src – src1 byte
PC ⇐ PC + 1
Flags Affected src is An:OF, SF, ZF, CF are set accordingly
src is Rx: RCF, RZF are set accordingly
Opcode
Instructions 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
CMPB An, imm8 1 0 1 0 0 1 1 An imm8
CMPB Rx, imm8 1 0 1 1 1 1 k4 k3 k2 k7 k6 k5 Rx k1 k0
Description Subtract value of src1 (zero filled in upper 8 bits) from src (i.e., src–src1) and
only modify the status flags. Contents of src not changed.
See Also CMP, CMPS, Jcc, Ccc
Example 4.14.11.1 CMPB A0, 0xf3
Compare immediate value 0xf3 to accumulator A0.
Example 4.14.11.2 CMPB R3, 0x21
Compare immediate value 0x21 to R3.