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

INSTRUCTION SET DESCRIPTIONSTable C-4. Instruction Set (Continued)Name Description OperationFlagsAffectedSTISTOSNOTE:Set Interrupt-enable Flag:STISets IF to 1, enabling processorrecognition of maskable interruptrequests appearing on the INTR line.Note however, that a pending interruptwill not actually be recognized until theinstruction following STI has executed.Instruction Operands:noneStore (Byte or Word) String:STOS dest-stringTransfers a byte or word from registerAL or AX to the string elementaddressed by DI and updates DI topoint to the next location in the string.As a repeated operation.Instruction Operands:STOS dest-stringSTOS (repeat) dest-string(IF) ← 1 AF –CF –DF –IF üOF –PF –SF –TF –ZF –When Source Operand is a Byte:(DEST) ← (AL)if(DF) = 0then(DI) ← (DI) + DELTAelse(DI) ← (DI) – DELTAWhen Source Operand is a Word:(DEST) ← (AX)if(DF) = 0then(DI) ← (DI) + DELTAelse(DI) ← (DI) – DELTAThe 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 executedAF –CF –DF –IF –OF –PF –SF –TF –ZF –C-44