dsp56000 Freescale Semiconductor, Inc, dsp56000 Datasheet - Page 354

• Manufacturer Part Number: dsp56000
• Description: 24-bit Digital Signal Processor Family Manual
• Manufacturer: Freescale Semiconductor, Inc

Operation:
SP+1
SP+1
1
SP+1
SP+1
1
SP+1
SP+1
1
SP+1
SP+1
1
SP+1
SP+1
1
SP+1
SP+1
1
End of Loop:
SSL(LF)
SSH
Description: Begin a hardware DO loop that is to be repeated the number of times spec-
ified in the instruction’s source operand and whose range of execution is terminated by
the destination operand (previously shown as “expr”). No overhead other than the execu-
tion of this DO instruction is required to set up this loop. DO loops can be nested and the
loop count can be passed as a parameter.
During the first instruction cycle, the current contents of the loop address (LA) and the
loop counter (LC) registers are pushed onto the system stack. The DO instruction’s
source operand is then loaded into the loop counter (LC) register. The LC register con-
tains the remaining number of times the DO loop will be executed and can be accessed
from inside the DO loop subject to certain restrictions. If LC equals zero, the DO loop is
A - 88
DO
LF
LF
LF
LF
LF
LF
LA;SSL
SP;LA
SP;PC
SP;LA
SP;PC
SP;LA
SP;PC
SP;LA
SP;PC
SP;LA
SP;PC
SP;LA
SP;PC
SR;SP–1
SSH;LC
SSH;LC
SSH;LC
SSH;LC
SSH;LC
SSH;LC
LC;SP – 1
SSH;SR
SSH;SR
SSH;SR
SSH;SR
SSH;SR
SSH;SR
Freescale Semiconductor, Inc.
SP
For More Information On This Product,
INSTRUCTION DESCRIPTIONS
INSTRUCTION SET DETAILS
SSL;X:ea
SSL;X:aa
SSL;Y:ea
SSL;Y:aa
SSL;#xxx
SSL;S
SSL;expr –1
SSL;expr –1
SSL;expr –1
SSL;expr –1
SSL;expr –1
SSL;expr –1
SP
Go to: www.freescale.com
Start Hardware Loop
LC
LC
LC
LC
LC
LC
LA
LA
LA
LA
LA
LA
Assembler Syntax:
DO
DO
DO
DO
DO
DO
X:ea,expr
X:aa,expr
Y:ea,expr
Y:aa,expr
#xxx,expr
S,expr
MOTOROLA
DO