Programmable Devices
CPLDs, FPGAs, SoC FPGAs, Configuration, and Transceivers

GCLK

Kai3325
Beginner
1,067 Views
I'm a beginner of FPGA designing.
I saw datasheet of MAX10, there isn't requirement of GCLK like jitter of input clock from external clock resource.
Is there any requirements about input clock?(ex. jitter, duty, etc...)
Labels (1)
0 Kudos
2 Replies
roeekalinsky
Valued Contributor I
1,034 Views

There certainly are clock input requirements/specifications for jitter, duty, etc. if you make use of the MAX10's PLL resources:

https://www.intel.com/content/www/us/en/docs/programmable/683794/current/pll-specifications.html 

 

If you don't use a PLL and just take your clock input straight into a global clock tree, then the jitter and duty characteristics of the incoming clock are just passed straight through the clock distribution to its endpoints.  And different endpoint resource types (logic elements, DSP blocks, memory blocks, etc.) each have different timing specs/requirements/limitations.  But these are static resources, so they wouldn't generally be sensitive to jitter, just to the minimum clock period.  And they wouldn't generally be sensitive to duty cycle per se, but they may have minimum clock high and low times that must be met, though this wouldn't typically become the limiting factor with anything close to 50% duty cycle.  Having said that, if your input clock has a duty cycle that isn't nominally 50%, then you should make sure to accurately reflect that in your timing constraints, so that static timing analysis in Quartus can properly analyze for it.

0 Kudos
cfkd
Employee
949 Views

As we do not receive any response from you on the previous question/reply/answer that we have provided. Please login to ‘https://supporttickets.intel.com’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you on your follow-up questions.


0 Kudos
Reply