Texas Instruments MSP430x4xx User Manual

Page 93

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Instruction Set

3-59

RISC 16−Bit CPU

* RLC[.W]

Rotate left through carry

* RLC.B

Rotate left through carry

Syntax

RLC

dst or

RLC.W

dst

RLC.B

dst

Operation

C <− MSB <− MSB−1 .... LSB+1 <− LSB <− C

Emulation

ADDC

dst,dst

Description

The destination operand is shifted left one position as shown in Figure 3−15.
The carry bit (C) is shifted into the LSB and the MSB is shifted into the carry
bit (C).

Figure 3−15. Destination Operand—Carry Left Shift

15

0

7

0

C

Byte

Word

Status Bits

N: Set if result is negative, reset if positive
Z: Set if result is zero, reset otherwise
C: Loaded from the MSB
V: Set if an arithmetic overflow occurs

the initial value is 04000h

dst < 0C000h; reset otherwise

Set if an arithmetic overflow occurs:
the initial value is 040h

dst < 0C0h; reset otherwise

Mode Bits

OSCOFF, CPUOFF, and GIE are not affected.

Example

R5 is shifted left one position.

RLC

R5

; (R5 x 2) + C −> R5

Example

The input P1IN.1 information is shifted into the LSB of R5.

BIT.B

#2,&P1IN

; Information −> Carry

RLC

R5

; Carry=P0in.1 −> LSB of R5

Example

The MEM(LEO) content is shifted left one position.

RLC.B

LEO

; Mem(LEO) x 2 + C −> Mem(LEO)

Note:

RLC and RLC.B Substitution

The assembler does not recognize the instruction:

RLC

@R5+.

It must be substituted by:

ADDC

@R5+,−2(R5).

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