LSL ACC,T
6-134
LSL ACC,T
Logical Shift Left by T(3:0)
SYNTAX OPTIONS
OPCODE
OBJMODE
RPT
CYC
LSL ACC,T
1111 1111 0101 0000
X
−
1
Operands
ACC
Accumulator register
T
Upper 16 bits of the multiplicand (XT) register
Description
Perform a logical shift left on the content of the ACC register by the amount
specified by the four least significant bits of the T register, T(3:0) = 0
…
15.
Higher order bits are ignored. During the shift, the low order bits of the ACC
register are zero filled. If T specifies a shift of 0, then C is cleared; otherwise,
C is filled with the last bit to be shifted out of the ACC register:
0
C
ACC
ACC
Last bit out or cleared
Discard other bits
Left shift
(Contents T(3:0)
Flags and
Modes
Z
After the shift, the Z flag is set if the ACC value is zero, else Z is cleared. Even
if the T register specifies a shift of 0, the content of the ACC register is still
tested for the zero condition and Z is affected.
N
After the shift, the N flag is set if bit 31 of the ACC is 1, else N is cleared. Even
if the T register specifies a shift of 0, the content of the ACC register is still
tested for the negative condition and N is affected.
C
If (T(3:0) = 0) then C is cleared; otherwise, the last bit shifted out is loaded
into the C flag bit.
Repeat
This instruction is not repeatable. If this instruction follows the RPT
instruction, it resets the repeat counter (RPTC) and executes only once.
Example
; Logical shift left contents of VarA by VarB:
MOVL ACC,@VarA
; ACC = VarA
MOV T,@VarB
; T = VarB (shift value)
LSL ACC,T
; Logical shift left ACC by T(3:0)
MOVL @VarA,ACC
; Store result into VarA
Содержание TMS320C28x
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Страница 269: ...IN loc16 PA 6 112 MOV AL 0 AL 0 UOUT IORegC AL IOspace IORegC AL 10...
Страница 308: ...MAXCUL P loc32 6 151 Saturate MOVL Var64 2 ACC Store result into Var64 MOVL Var64 P...
Страница 509: ...SUBL ACC P PM 6 352 SUBL ACC P PM ACC S B 11 M X 4 MOVH Y ACC 5 Store Q15 result into Y...
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