Instruction Formats - Texas Instruments C28 Series Student Manual

Instruction Formats

The C28x follows a convention that uses instruction, destination, then source operand order
(INSTR dst, src). Several general formats exist to allow modification of memory or registers
based on constants, memory, or register inputs. Different modes are identifiable by their leading
characters (# for immediate, * for indirect, and @ for direct). Note that registers or data memory
can be selected as a 'mem' value.
C28x - Appendix B - Addressing Modes
Instruction Formats
Instruction Formats
INSTR dst , src
INSTR dst , src
INSTR INSTR REG REG
INSTR REG,# imm
INSTR REG,# imm
INSTR REG, mem
INSTR REG, mem
INSTR INSTR mem mem ,REG ,REG
INSTR INSTR mem mem ,# ,# imm imm
What is a "REG"?
What is a "REG"?
16 - bit Access = AR0 through AR7, AH, AL, PH, PL, T and SP
16 - bit Access = AR0 through AR7, AH, AL, PH, PL, T and SP
32 32 - - bit Access = XAR0 through XAR7, ACC, P, XT bit Access = XAR0 through XAR7, ACC, P, XT
What is an "# imm "?
What is an "# imm "?
an immediate constant stored in the instruction an immediate constant stored in the instruction
What is a " mem "?
What is a " mem "?
A directly or indirectly addressed operand from data memory
A directly or indirectly addressed operand from data memory
Or, one of the registers from "REG"! Or, one of the registers from "REG"!
loc16 or loc32 (for 16
loc16 or loc32 (for 16
Example
Example
NEG NEG AL AL
MOV ACC,#1
MOV ACC,#1
ADD AL,@x
ADD AL,@x
SUB SUB AL,@AR0 AL,@AR0
MOV MOV *XAR0++,#25 *XAR0++,#25
- bit or 32 - bit data access)
- bit or 32 - bit data access)
Instruction Formats
B - 5