dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 433

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

CLR.B
Operation:
0 → D
Description: Set a byte in memory to zero. Addresses are expressed as word pointers.
Example:
Explanation of Example:
Condition Codes Affected:
Instruction Fields:
Instruction Opcodes:
Timing:
Memory:
Freescale Semiconductor
CLR.B
CLR.B
CLR.B
Operation
CLR.B
Before Execution
X:(Rn+xxxx)
X:(Rn+xxxxxx)
X:(SP)
(no parallel move)
CLR.B
The contents of the upper byte from stack address $004442 are cleared.
The condition codes are not affected by this instruction.
1–3 oscillator clock cycle(s)
1–3 program word(s)
SP
X:$4443
X:$4442
X:(SP-1)
X:(Rn+xxxxxx)
X:(Rn+xxxx)
Operands
X:(SP)
Clear Byte (Word Pointer)
004443
3333
2222
15
15
15
1
1
1
1
Instruction Set Details
1
1
1
1
; clear a byte in the stack
C
1
2
3
0
1
0
0
Assembler Syntax:
CLR.B
W
12
12
12
1
2
3
1
0
1
1
Clear a byte in memory using appropriate addressing
mode
11
11
11
1
0
1
1
After Execution
0
A
0
0
AAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAA
A
0
0
0
D
A
1
1
1
8
8
8
SP
X:$4443
X:$4442
7
1
7
0
1
7
1
(no parallel move)
Comments
1
A
1
0
1
1
1
1
004443
0
1
0
1
4
4
4
3333
0022
R
R
A
1
3
3
3
CLR.B
0
A
0
1
R
A
R
1
R
A
R
1
A-89
0
0
0