Read Modify Write Operations - Texas Instruments C28 Series Student Manual

Read Modify Write Operations

Read Modify Write Operations
The accumulator (ACC) is the main working register for the C28x. It is the destination of all
ALU operations except those, which operate directly on memory or registers. The accumulator
supports single-cycle move, add, subtract and compare operations from 32-bit-wide data memory.
It can also accept the 32-bit result of a multiplication operation. These one or two cycle
operations are referred to as read-modify-write operations, or as atomic instructions.
AND
OR
XOR
ADD
SUB
SUBR loc16,AX
INC
DEC
C - 18
Read-Modify-Write Instructions
Work directly on memory
Work directly on memory
Atomic Operations
Atomic Operations
loc16,AX
loc16,AX
loc16,AX
AH,
AL
loc16,AX
loc16,AX
loc16
loc16
– bypass ACC
– bypass ACC
– protected from interrupts
– protected from interrupts
AND loc16,#16b
OR loc16,#16b
XOR loc16,#16b
ADD loc16,#16b
SUBR loc16,#16b
TSET loc16,#bit
TCLR loc16,#bit
C28x - Appendix C - Assembly Programming
16- bit
constant