Intel 80C188XL User Manual

Page 332

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C-9

INSTRUCTION SET DESCRIPTIONS

CLI

Clear Interrupt-enable Flag:

CLI

Zeroes the interrupt-enable flag (IF).
When the interrupt-enable flag is
cleared, the 8086 and 8088 do not
recognize an external interrupt request
that appears on the INTR line; in other
words maskable interrupts are
disabled. A non-maskable interrupt
appearing on NMI line, however, is
honored, as is a software interrupt.

Instruction Operands:

none

(IF)

0

AF –
CF –
DF –
IF

ü

OF –
PF –
SF –
TF –
ZF –

CMC

Complement Carry Flag:

CMC

Toggles complement carry flag (CF) to
its opposite state and affects no other
flags.

Instruction Operands:

none

if

(CF) = 0

then

(CF)

1

else

(CF)

0

AF –
CF

ü

DF –
IF –
OF –
PF –
SF –
TF –
ZF –

Table C-4. Instruction Set (Continued)

Name

Description

Operation

Flags

Affected

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

ü

the flag is updated after the instruction is executed

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