Freescale Semiconductor SC140 Benutzerhandbuch
NOP
SC140 DSP Core Reference Manual
A-333
NOP
No Operation (PREFIX)
NOP
Description
Status and conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
nop
Instruction Formats and Opcodes
Operation
Assembler Syntax
no operation
NOP
NOP
This instruction is encoded as a one-word prefix inside the set, or alone. If the NOP is the only instruction
in the execution set, it takes one cycle to execute although no operation is done. This is useful in case
delays are needed in a program for various reasons (for example, to account for pipeline delays). The NOP
instruction is not dispatched to any execution unit. As a prefix, it is identified by the dispatcher and is not
dispatched further.
in the execution set, it takes one cycle to execute although no operation is done. This is useful in case
delays are needed in a program for various reasons (for example, to account for pipeline delays). The NOP
instruction is not dispatched to any execution unit. As a prefix, it is identified by the dispatcher and is not
dispatched further.
If grouped with other instructions (as an intra-group NOP), it functions as a program place-holder.
In a few isolated cases, the assembler adds this instruction inside an execution set to help arrange the
instructions within that set for proper dispatching. These cases are implementation-dependent. The
assembler issues a warning to make the user aware of the event.
instructions within that set for proper dispatching. These cases are implementation-dependent. The
assembler issues a warning to make the user aware of the event.
Instruction
Words Cycles Type
Opcode
15
8
7
0
NOP
1
1
4
1
0
0
1
0
0
0
0
1
1
0
0
0
0
0
0