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Aigneryu

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maximum integer in verilog-A/AMS
Jan 13^th, 2009, 8:24am

I thought 32-bit integer can be used in verilog-A; however, it may not be the case. I tried to use an integer variable/parameter in verilog-A model in spectre simulation, but the system told me that only maximum 2097152 is allowed.

Does anyone have this problem before? I need an at least 24bit unsigned integer. I have tried if it is due to the parameter or the integer variable, I used both in my model.

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Andrew Beckett

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Re: maximum integer in verilog-A/AMS
Reply #1 - Jan 13^th, 2009, 9:59am

Really? From my quick experiment, the largest integer is 2147483647 (2^31-1) which is reasonable if it is signed. I tried in both the latest MMSIM70 Hotfix, and IC5141 (so quite an old release of spectre).

Which version of spectre are you using? Can you post the code example that breaks?

It seems a bit odd that the number you gave is 2^21
Regards,

Andrew.

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Aigneryu Senior Member Offline Posts: 102	Re: maximum integer in verilog-A/AMS Reply #2 - Jan 13^th, 2009, 11:49am My mistake. I just found it was my mistake. I put a upper bound on the parameter hidden somewhere in the long code. I also confirmed that the integer can go up to 2^31. Thanks.
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neoflash Community Fellow Offline Mixed-Signal Designer Posts: 397	Re: maximum integer in verilog-A/AMS Reply #3 - Sep 18^th, 2010, 10:35pm How can we enable a number even larger? say, 2^128 ? Aigneryu wrote on Jan 13^th, 2009, 11:49am: My mistake. I just found it was my mistake. I put a upper bound on the parameter hidden somewhere in the long code. I also confirmed that the integer can go up to 2^31. Thanks.
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pancho_hideboo Senior Fellow Offline Posts: 1424 Real Homeless	Re: maximum integer in verilog-A/AMS Reply #4 - Sep 18^th, 2010, 11:03pm neoflash wrote on Sep 18^th, 2010, 10:35pm: How can we enable a number even larger? say, 2^128 ? Treat it by four subblocks with 32bit bus width.
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neoflash Community Fellow Offline Mixed-Signal Designer Posts: 397	Re: maximum integer in verilog-A/AMS Reply #5 - Sep 18^th, 2010, 11:22pm Good idea. I just did so for a 64/66 scrambler.
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