Instruction Set Description
263
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
CPUX
4.6.4.6
DECDA
* DECDA
Double-decrement 20-bit destination register
Syntax
DECDA Rdst
Operation
Rdst – 2
→
Rdst
Emulation
SUBA #2,Rdst
Description
The destination register is decremented by 2. The original contents are lost.
Status Bits
N:
Set if result is negative, reset if positive
Z:
Set if Rdst contained 2, reset otherwise
C:
Reset if Rdst contained 0 or 1, set otherwise
V:
Set if an arithmetic overflow occurs, otherwise reset
Mode Bits
OSCOFF, CPUOFF, and GIE are not affected.
Example
The 20-bit value in R5 is decremented by 2.
DECDA
R5
; Decrement R5 by 2