80C186EB/80C188EB Microprocessor User's Manual - CEUNES

INSTRUCTION SET DESCRIPTIONSTable C-4. Instruction Set (Continued)Name Description OperationSUBTESTNOTE:Subtract:SUB dest, srcThe source operand is subtracted fromthe destination operand, and the resultreplaces the destination operand. Theoperands may be bytes or words. Bothoperands may be signed or unsignedbinary numbers (see AAS and DAS).Instruction Operands:SUB reg, regSUB reg, memSUB mem, regSUB accum, immedSUB reg, immedSUB mem, immedTest:TEST dest, srcPerforms the logical "and" of the twooperands (bytes or words), updatesthe flags, but does not return theresult, i.e., neither operand ischanged. If a TEST instruction isfollowed by a JNZ (jump if not zero)instruction, the jump will be taken ifthere are any corresponding one bitsin both operands.Instruction Operands:TEST reg, regTEST reg, memTEST accum, immedTEST reg, immedTEST mem, immed(dest) ← (dest) – (src)(dest) and (src)(CF ) ← 0(OF) ← 0The three symbols used in the Flags Affected column are defined as follows:– the contents of the flag remain unchanged after the instruction is executed? the contents of the flag is undefined after the instruction is executedüthe flag is updated after the instruction is executedFlagsAffectedAF üCF üDF –IF –OF üPF üSF üTF –ZF üAF ?CF üDF –IF –OF üPF üSF üTF –ZF üC-45