A-400
SC140 DSP Core Reference Manual
SXT.x
SXT.x
Sign-Extension (DALU)
SXT.x
Description
These operations sign-extend a data register. The sign bit (bit 7 in a byte, bit 15 in a word, and bit 31 in a
long word) is copied to the upper bits in a 40-bit data register.
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Example 1
sxt.b d3,d0
Example 2
sxt.w d3,d2
Operation
Assembler Syntax
Da[7:0]
→
Dn[7:0]; Da[7]
→
Dn[39:8]
SXT.B Da,Dn
Da[15:0]
→
Dn[15:0]; Da[15]
→
Dn[39:16]
SXT.W Da,Dn
Dn[31]
→
Dn[39:32]
SXT.L Dn
SXT.B Da,Dn
Sign-extends a byte from a source data register (Da[7:0]) into a destination data register (Dn).
SXT.W Da,Dn
Sign-extends a word from a source data register (Da[15:0]) into a destination data register (Dn).
SXT.L Dn
Sign-extends a long word from a source data register (Dn[31:0]) into a destination data register (Dn).
Register Address
Bit Name
Description
Ln
L
Clears the Ln bit in the destination register.
Register/Memory Address
Before
After
D3
$FF FE34 A086
L0:D0
$0:$FF FFFF FF86
Register/Memory Address
Before
After
D3
$00 0000 7056
Summary of Contents for SC140 DSP Core
Page 12: ...xii SC140 DSP Core Reference Manual ...
Page 18: ...xviii SC140 DSP Core Reference Manual ...
Page 32: ...1 6 SC140 DSP Core Reference Manual Core Architecture Features ...
Page 180: ...4 70 SC140 DSP Core Reference Manual Trace Unit Registers ...
Page 250: ...6 70 SC140 DSP Core Reference Manual Programming Rules ...
Page 314: ...7 64 SC140 DSP Core Reference Manual NOP Definition ...
Page 463: ...DI SC140 DSP Core Reference Manual A 149 15 8 7 0 DI 1 1 4 1 0 0 1 1 1 1 1 0 1 1 1 1 1 0 1 ...
Page 478: ...A 164 SC140 DSP Core Reference Manual EI ...
Page 618: ...A 304 SC140 DSP Core Reference Manual MOVES 4F s15 sssssssssssssss Signed 15 bit offset ...
Page 638: ...A 324 SC140 DSP Core Reference Manual MPYR ...
Page 746: ...A 432 SC140 DSP Core Reference Manual ZXTA x ...
Page 758: ...I 10 Index ...
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