ASR AX,T
6-54
ASR AX,T
Arithmetic Shift Right
SYNTAX OPTIONS
OPCODE
OBJMODE
RPT
CYC
ASR AX,T
1111 1111 0110 010A
X
−
1
Operands
AX
Accumulator high (AH) or accumulator low (AL) register
T
Upper 16 bits of the multiplicand (XT) register
Description
Perform an arithmetic shift right on the content of the specified AX register as
specified by the four least significant bits of the T register, T(3:0) = shift
value = 0
…
15. The contents of higher order bits are ignored. During the shift,
the value is sign extended. If the T(3:0) register bits specify a shift of 0, then C
is cleared; otherwise, C is filled with the last bit to be shifted out of AX:
SIGN
C
AX
AX
Last bit out or cleared
Right shift
(Contents of T [3:0])
Discard other bits
Flags and
Modes
N
After the shift, if bit 15 of AX is 1 then the negative flag bit is set; otherwise it is
cleared. Even if the T(3:0) register bits specify a shift of 0, the value of AH or
AL is still tested for the negative condition and N is affected.
Z
After the shift, if AX is 0, then the Z bit is set, otherwise it is cleared. Even if the
T(3:0) register bits specify a shift of 0, the value of AH or AL is still tested for the
zero condition and Z is affected.
C
If T(3:0) specifies a shift of 0, then C is cleared; otherwise, C is filled with the
last bit to be shifted out of AH or AL.
Repeat
This instruction is not repeatable. If this instruction follows the RPT
instruction, it resets the repeat counter (RPTC) and executes only once.
Example
; Calculate signed value: VarC = VarA >> VarB;
MOV T,@VarB
; Load T with contents of VarB
MOV AL,@VarA
; Load AL with contents of VarA
ASR AL,T
; Scale AL by value in T bits 0 to 3
MOV @VarC,AL
; Store result in VarC
Содержание TMS320C28x
Страница 30: ...1 12...
Страница 80: ...This page intentionally left blank 2 50 This page intentionally left blank...
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...
Страница 585: ...This page intentionally left blank 7 32 This page intentionally left blank...