Sbrk – Texas Instruments TMS320C2XX User Manual
Page 307
SBRK
Subtract Short-Immediate Value From Auxiliary Register
7-154
Syntax
SBRK #
k
Short immediate addressing
Operands
k:
8-bit positive short immediate value
SBRK #
k
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
1
1
1
1
0
0
k
Execution
Increment PC, then ...
(current AR) – k
→
current AR
Note that k is an 8-bit positive constant.
Status Bits
None
Description
The 8-bit immediate value is subtracted, right justified, from the content of the
current auxiliary register (the one pointed to by the ARP) and the result re-
places the contents of the auxiliary register. The subtraction takes place in the
auxiliary register arithmetic unit (ARAU), with the immediate value treated as
an 8-bit positive integer. All arithmetic operations on the auxiliary registers are
unsigned.
Words
1
Cycles for a Single SBRK Instruction
ROM
DARAM
SARAM
External
1
1
1
1+p
Example
SBRK
#0FFh
Before Instruction
After Instruction
ARP
7
ARP
7
AR7
0h
AR7
FF01h
Opcode
Cycles