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15
0
7
0
C
Byte
Word
Instruction Set Description
4.6.2.39 RLC
* 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
ADDC dst,dst
Emulation
Description
The destination operand is shifted left one position as shown in
. The carry bit
(C) is shifted into the LSB, and the MSB is shifted into the carry bit (C).
Figure 4-39. Destination Operand—Carry Left Shift
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:
RLA substitution
The assembler does not recognize the instructions:
RLC
@R5+
RLC.B
@R5+
RLC(.B) @R5
They must be substituted by:
ADDC
@R5+,-2(R5)
ADDC.B
@R5+,-1(R5)
ADDC(.B) @R5
172
CPUX
SLAU272C – May 2011 – Revised November 2013
Copyright © 2011–2013, Texas Instruments Incorporated