Datapath, using carry output as shift input in the same cycle possible?

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RaAl_264636
Level 6
Level 6
50 sign-ins 25 sign-ins 10 solutions authored

Hello,

is it possible to use the carry output of a datapath ADD/SUB operation as the shift input in the same cycle?

Regards

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Ekta_N
Moderator
Moderator
Moderator
750 replies posted First like given 250 solutions authored

Hello @RaAl_264636 

If you go through the simplified Datapath Architecture the ALU which is capable of performing add and subtract operation is separate from the shifter block.

Ekta_0-1657086030126.png

 

Therefore, It should be possible to perform the shift and add/sub operation within the same cycle.

When using the UDB Editor to configure the Datapath, it is possible to configure both add/sub and shift operation in a single instruction:

Ekta_1-1657086619299.png

Best Regards
Ekta

 

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RaAl_264636
Level 6
Level 6
50 sign-ins 25 sign-ins 10 solutions authored

Hello @Ekta_N 

using the ADD/SUB operation in combination with shift is no problem, many components use this - but the question is if it's possible to use the carry bit from an ADD/SUB operation as the shift input in the same cycle. Something like this:

RaAl_264636_0-1657090075672.png

Regards

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