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Adventurer
Adventurer
3,502 Views
Registered: ‎10-18-2014

input order of LUTs after Synthesis

Hi every body,

After design synthesis, we can see the schematic view of design including LUTs. In addition, we can see the truth table of LUTs. My questions are:

1- Are the input order of LUTs changed after place and route? (This leads to a different truth table in comparison with the synthesis step)

2- Can we edit  contents of LUTs after synthesis and before the mapping step?

 

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Moderator
Moderator
3,481 Views
Registered: ‎07-01-2015

Re: input order of LUTs after Synthesis

Hi @farzian,

 

We expect the functionality of synthesized design and implemented design. As far as implementation is concerned it has flexibility of swapping the lut pins(mapping to lut primitive)only if original functionality is not altered. You can change INIT value of the LUT to realise different truth table.

Thanks,
Arpan
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Moderator
Moderator
3,366 Views
Registered: ‎07-21-2014

Re: input order of LUTs after Synthesis

@farzian

 

1- Are the input order of LUTs changed after place and route? (This leads to a different truth table in comparison with the synthesis step)

>>Yes, there are few scenarios where tool might change the LUT pins, but this change should not affect the design functionality.

 

2- Can we edit  contents of LUTs after synthesis and before the mapping step?

>>Yes, you can change the LUT contents after synthesis.

 

Thanks,
Anusheel
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