xxxxh
Address
Space
D546h
PC
21036h
21034h
AA550h
11111h
R5
R6
Register
Before:
Address
Space
PC
AA550h
BB551h
R5
R6
Register
After:
AA550h.or.11111h = BB551h
1800h
21032h
xxxxh
D546h
21036h
21034h
1800h
21032h
xxxxh
Address
Space
D506h
PC
21036h
21034h
AA550h
11111h
R5
R6
Register
Before:
xxxxh
Address
Space
D506h
PC
21036h
21034h
AA550h
0B551h
R5
R6
Register
After:
A550h.or.1111h = B551h
Addressing Modes
123
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
CPUX
4.4.1 Register Mode
Operation:
The operand is the 8-, 16-, or 20-bit content of the used CPU register.
Length:
1, 2, or 3 words
Comment:
Valid for source and destination
Byte operation:
Byte operation reads only the 8 least significant bits (LSBs) of the source register
Rsrc and writes the result to the 8 LSBs of the destination register Rdst. The bits
Rdst.19:8 are cleared. The register Rsrc is not modified.
Word operation:
Word operation reads the 16 LSBs of the source register Rsrc and writes the result
to the 16 LSBs of the destination register Rdst. The bits Rdst.19:16 are cleared.
The register Rsrc is not modified.
Address-word
operation:
Address-word operation reads the 20 bits of the source register Rsrc and writes the
result to the 20 bits of the destination register Rdst. The register Rsrc is not
modified
SXT exception:
The SXT instruction is the only exception for register operation. The sign of the low
byte in bit 7 is extended to the bits Rdst.19:8.
Example:
BIS.W R5,R6 ;
This instruction logically ORs the 16-bit data contained in R5 with the 16-bit
contents of R6. R6.19:16 is cleared.
Example:
BISX.A R5,R6 ;
This instruction logically ORs the 20-bit data contained in R5 with the 20-bit
contents of R6.
The extension word contains the A/L bit for 20-bit data. The instruction word uses
byte mode with bits A/L:B/W = 01. The result of the instruction is: