MSB
C
0
LSB
0
Instruction Set Description
236
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
CPUX
4.6.3.23 RLAX
* RLAX.A
Rotate left arithmetically address-word
* RLAX.[W]
Rotate left arithmetically word
* RLAX.B
Rotate left arithmetically byte
Syntax
RLAX.A dst
RLAX dst
or
RLAX.W dst
RLAX.B dst
Operation
C
←
MSB
←
MSB-1 .... LSB+1
←
LSB
←
0
Emulation
ADDX.A dst,dst
ADDX dst,dst
ADDX.B dst,dst
Description
The destination operand is shifted left 1 position as shown in
. The MSB is
shifted into the carry bit (C) and the LSB is filled with 0. The RLAX instruction acts as a
signed multiplication by 2.
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:
.A: Set if an arithmetic overflow occurs: the initial value is 040000h
≤
dst <
0C0000h; reset otherwise
.W: Set if an arithmetic overflow occurs: the initial value is 04000h
≤
dst < 0C000h;
reset otherwise
.B: 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
The 20-bit value in R7 is multiplied by 2
RLAX.A
R7
; Shift left R7 (20-bit)
Figure 4-45. Destination Operand-Arithmetic Shift Left