INSTRUCTION SET DESCRIPTIONS

Table C-4. Instruction Set (Continued)

Name

Description

Operation

Flags

Affected

 

 

 

 

 

 

 

INC

Increment:

(dest) (dest) + 1

AF

 

INC dest

 

CF –

 

 

DF –

 

Adds one to the destination operand.

 

 

 

IF –

 

The operand may be byte or a word

 

 

 

OF

 

and is treated as an unsigned binary

 

 

 

PF

 

number (see AAA and DAA).

 

 

 

SF

 

Instruction Operands:

 

 

 

TF –

 

INC reg

 

ZF ¸

 

INC mem

 

 

 

 

 

 

INS

In String:

(dest) (src)

AF –

 

INS dest-string, port

 

CF –

 

 

DF –

 

Performs block input from an I/O port

 

 

 

IF –

 

to memory. The port address is placed

 

 

 

OF –

 

in the DX register. The memory

 

 

 

PF –

 

address is placed in the DI register.

 

 

 

SF –

 

This instruction uses the ES register

 

 

 

TF –

 

(which cannot be overridden). After the

 

 

 

ZF –

 

data transfer takes place, the DI

 

 

 

 

 

register increments or decrements,

 

 

 

depending on the value of the direction

 

 

 

flag (DF). The DI register changes by 1

 

 

 

for byte transfers or 2 for word

 

 

 

transfers.

 

 

 

Instruction Operands:

 

 

 

INS dest-string, port

 

 

 

INS (repeat) dest-string, port

 

 

 

 

 

 

NOTE: The 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 executed

the flag is updated after the instruction is executed

C-18

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Intel 80C186XL, 80C188XL user manual Increment, String, INS dest-string, port