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RDobk's avatar
RDobk
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7 years ago

NCO IP Core Reset_N and CLKEN functions

Hi,

What are the requirements for Reset_N and CLKEN timing?

  1. Is there any minimal width for RESET_N in terms of clock cycles?
  2. Should assertion of CLKEN always precede the RESET_N de-assertion (reset release)? if so, by how many clock cycles?
  3. Are there any additional requirements for timing for RESET_N (e.g. should it de-assertion be synchronized to the clock of the NCO)?

Thank you!

--Reuven.

2 Replies

    • RDobk's avatar
      RDobk
      Icon for New Contributor rankNew Contributor
      7 years ago
      Hi, I am familiar with this document. Unfortunately, it does not answer my questions: 1. Is there any minimal width for RESET_N in terms of clock cycles? 2. Should assertion of CLKEN always precede the RESET_N de-assertion (reset release)? if so, by how many clock cycles? 3. Are there any additional requirements for timing for RESET_N (e.g. should it de-assertion be synchronized to the clock of the NCO)? In the lab, I observe that Enabling the NCO after reset de-assertion has a non-deterministic effect on the NCO output – after such reset the NCO initial delay (reset/Clken -> DV_OUT) is non deterministic. Thus the questions is, what is the correct order/way to reset and then leave the reset for the NCO. Best regards, --Reuven.