Texas Instruments MSP430x1xx, User Manual

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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).