Intel 80C188XL User Manual

Page 364

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C-41

INSTRUCTION SET DESCRIPTIONS

SBB

Subtract With Borrow:

SBB

dest, src

Subtracts the source from the desti-
nation, subtracts one if CF is set, and
returns the result to the destination
operand. Both operands may be bytes
or words. Both operands may be
signed or unsigned binary numbers
(see AAS and DAS)

Instruction Operands:

SBB reg, reg
SBB reg, mem
SBB mem, reg
SBB accum, immed
SBB reg, immed
SBB mem, immed

if

(CF) = 1

then

(dest) = (dest) – (src) – 1

else

(dest)

(dest) – (src)

AF

ü

CF

ü

DF –
IF –
OF

ü

PF

ü

SF

ü

TF –
ZF

ü

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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