Texas Instruments MSP430x1xx User Manual

Page 389

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Instruction Set Overview

B-39

Instruction Set Description

JNC

Jump if carry not set

JLO

Jump if lower

Syntax

JNC

label

JNC

label

Operation

if C = 0: PC + 2

×

offset –> PC

if C = 1: execute following instruction

Description

The status register carry bit (C) is tested. If it is reset, the 10-bit signed offset
contained in the instruction LSBs is added to the program counter. If C is set,
the next instruction following the jump is executed. JNC (jump if no carry/lower)
is used for the comparison of unsigned numbers (0 to 65536).

Status Bits

Status bits are not affected.

Example

The result in R6 is added in BUFFER. If an overflow occurs, an error handling
routine at address ERROR is used.

ADD

R6,BUFFER

; BUFFER + R6 –> BUFFER

JNC

CONT

; No carry, jump to CONT

ERROR

......

; Error handler start

......
......
......

CONT

......

; Continue with normal program flow

......
......

Example

Branch to STL 2 if byte STATUS contains 1 or 0.

CMP.B

#2,STATUS

JLO

STL 2

; STATUS < 2

......

; STATUS

2, continue here

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