Forum Discussion
ContributorArial10 Power-Up Calibration Clock Question
Hi @xytech
Calibration starts during configuration.
No timing sequence, the time for calibration to complete vary by device.
Based on experience, faster configuration time is needed if you are designing for open-system to meet the 100ms. For closed-system, you can adjust the PERST to allow more time.
Hope this helps.
Frequent ContributorHi @xytech,
There are two main types of calibration.
• Power-up calibration—Initiates automatically at device power-up and runs during device configuration.
• User calibration—If you perform dynamic reconfiguration or change the reference clock frequency of the I/O PLL, you must perform user recalibration. You must enable the required calibration sequence.
With that, answer to "Is it start AFTER or parallel with Configuration Starting Moment?" should be parallel with the configuration process.
There is no timing sequence for the calibration process as the time required after device power-up to complete the calibration process can vary by device. That's why you will need the cal_busy signal to know when it completes.
Just my 2 cents, as to ASx4 to FPP, I think it depends the PCIe is used for open-system (need to meet 100ms requirement) or closed-system (up to you to decide). If it is a closed-system, I dont see why you need to change to FPP, you can delay the #PERST to allow more time.
I hope this helps.
