CPU Registers
2-8
Table 2
−
2. Available Operations for Shifting Values in the Accumulator
Register
Shift Direction
Shift Type
Instruction
ACC
Left
Logical
LSL or LSLL
Rotation
ROL
Right
Arithmetic
SFR with SXM = 1
or ASRL
Logical
SFR with SXM = 0
or LSRL
Rotation
ROR
AH or AL
Left
Logical
LSL
Right
Arithmetic
ASR
Logical
LSR
2.2.2 Multiplicand Register (XT)
The multiplicand register (XT register) is used primarily to store a 32-bit signed
integer value prior to a 32-bit multiply operation.
The lower 16-bit portion of the XT register is referred to as the TL register. This
register can be loaded with a signed 16-bit value that is automatically sign-ex-
tended to fill the 32-bit XT register.
The upper 16-bit portion of the XT register is referred to as the T register. The
T register is mainly used to store a 16-bit integer value prior to a 16-bit multiply
operation.
The T register is also used to specify the shift value for some shift operations.
In this case, only a portion of the T register is used, depending on the instruc-
tion.
For example:
ASR AX, T
performs an arithmetic shift right
based on the four least significant bits
of T: T(3:0) = 0...15
ASRL ACC, T
performs an arithmetic shift right by
the five least significant bits of T:
T(4:0) 0...31
For these operations, the most significant bits of T are ignored.
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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