dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 630

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

SXTA.W
Operation:
S[15] → D[23:16]
Description: Take the word that is located in the low-order 16 bits of the destination AGU address register, and sign
Example:
Explanation of Example:
Condition Codes Affected:
Instruction Fields:
Instruction Opcodes:
Timing:
Memory:
A-286
SXTA.W Rn
Operation
SXTA.W
Before Execution
R2
extend it to fill all 24 bits, replicating bit 15 through bits 23–16.
SXTA.W R2
Initially, the R2 AGU register holds the value $0083F7. After the SXTA.W R2 instruction is executed,
bit 15 is replicated through the high-order 8 bits. The result is $FF83F7.
The condition codes are not affected by this instruction.
1 oscillator clock cycle
1 program word
(no parallel move)
Operands
0083F7
Rn
Sign Extend Word in AGU Register
DSP56800E Core Reference Manual
15
1
C
1
0
; sign extend word in R2
W
1
0
Assembler Syntax:
SXTA.W
Sign extend the value in an AGU register from bit 15
12
0
11
0
After Execution
R2
1
0
D
1
8
FF83F7
Comments
7
1
(no parallel move)
0
Freescale Semiconductor
1
SXTA.W
0
4
R
3
1
R
R
0