Repeat Single Instruction
RPTS
13-211
Assembly Language Instructions
Syntax
RPTS
src
Operation
src
→
RC
1
→
ST (RM)
1
→
S
Next PC
→
RS
Next PC
→
RE
Operands
src general addressing modes (G):
0 0
register
0 1
direct
1 0
indirect (disp = 0–255, IR0, IR1)
1 1
immediate
Opcode
31
24 23
16
8 7
0
15
0 0 0
1 0
1
1
1
0
1
src
G
1
1 1
0
Description
The RPTS instruction allows you to repeat a single instruction
src + 1 times
without any penalty for looping. Fetches can also be made from the instruction
register (IR), thus avoiding repeated memory access.
The
src operand is loaded into the repeat counter (RC). A 1 is written into the
repeat mode bit of the status register ST (RM). A 1 is also written into the re-
peat single bit (S). This indicates that the program fetches are to be performed
only from the instruction register. The next PC is loaded into the repeat end-ad-
dress (RE) register and the repeat start-address (RS) register.
For the immediate mode, the
src operand is assumed to be an unsigned inte-
ger and is not sign extended.
Cycles
4
Status Bits
LUF
Unaffected
LV
Unaffected
UF
Unaffected
N Unaffected
Z
Unaffected
V
Unaffected
C
Unaffected
OVM
Operation is not affected by OVM bit value.
Mode Bit