PDSP1601_96 Datasheet, PDF (12/18 Pages) Mitel Networks Corporation – ALU and Barrel Shifter

PDSP1601/PDSP1601A
Mnemonic
LR1SV
LR2SV
ASRSV
ASRR1
ASRR2
NRMXX
NRMR1
NRMR2
Op Code
<8>
<9>
<A>
<B>
<C>
<D>
<E>
<F>
Function
On the rising edge of CLK at the end of the cycle in which this instruction is executing, the
R1 register will be loaded with the data present on the SV port. The input to the Barrel
Shifter will be passed onto the output unshifted.
On the rising edge of CLK at the end of the cycle in which this instruction is executing, the
R2 register will be loaded with the data present on the SV port. The input to the Barrel
Shifter will be passed onto the output unshifted.
The 16 bit input to the Barrel Shifter is right shifted by the number of places indicated by
the magnitude of the four bit number present in the SV register. The LSBs are discarded,
and the vacant MSBs are filled with duplicates of the original MSB. (Sign Extension).
The 16 bit input to the Barrel Shifter is right shifted by the number of places indicated by
the magnitude of the four bit number resident within the R1 register. The LSBs are
discarded, and the vacant MSBs are filled with duplicates of the original MSB.
(Sign Extension).
The 16 bit input to the Barrel Shifter is right shifted by the number of places indicated by
the magnitude of the four bit number resident within the R2 register. The LSBs are
discarded, and the vacant MSBs are filled with duplicates of the original MSB.
(Sign Extension).
The 16 bit input to the Barrel Shifter is left shifted by the number of places indicated by the
magnitude of the four bit number output from the Priority Encoder. This value is also output
on the SV port (provided SVOE is low).
The effect of this operation is to left shift the input by the necessary amount
(max 15 places) to result in the MSB and the next most significant bit being different. This
has the effect of eliminating unnecessary Sign Bits, and hence Normalising the input data.
The MSBs shifted out to the left are discarded, and the vacant LSBs on the right are filled
with zeros.
The 16 bit input to the Barrel Shifter is left shifted by the number of places indicated by the
magnitude of the four bit number output from the Priority Encoder. This value is also loaded
into the R1 register at the end of the cycle, and is output on the SV port (provided SVOE
is low).
The effect of this operation is to left shift the input by the necessary amount
(max 15 places) to result in the MSB and the next most significant bit being different. This
has the effect of eliminating unnecessary Sign Bits, and hence Normalising the input data.
The MSBs shifted out to the left are discarded, and the vacant LSBs on the right are filled
with zeros.
The 16 bit input to the Barrel Shifter is left shifted by the number of places indicated by the
magnitude of the four bit number output from the Priority Encoder. This value is also loaded
into the R2 register at the end of the cycle, and is output on the SV port (provided SVOE
is low).
The effect of this operation is to left shift the input by the necessary amount
(max 15 places) to result in the MSB and the next most significant bit being different. This
has the effect of eliminating unnecessary Sign Bits, and hence Normalising the input data.
The MSBs shifted out to the left are discarded, and the vacant LSBs on the right are filled
with zeros.
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