Instruction Set Description
225
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
CPUX
4.6.3.13 DECDX
* DECDX.A
Double-decrement destination address-word
* DECDX.[W]
Double-decrement destination word
* DECDX.B
Double-decrement destination byte
Syntax
DECDX.A dst
DECDX dst
or
DECDX.W dst
DECDX.B dst
Operation
dst – 2
→
dst
Emulation
SUBX.A #2,dst
SUBX #2,dst
SUBX.B #2,dst
Description
The destination operand is decremented by 2. The original contents are lost.
Status Bits
N:
Set if result is negative, reset if positive
Z:
Set if dst contained 2, reset otherwise
C:
Reset if dst 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
RAM address-word TONI is decremented by 2.
DECDX.A
TONI
; Decrement TONI