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FabriceNs's avatar
FabriceNs
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3 days ago

Cyclone 10 GX Transceiver Power-Up Calibration Time (~353 ms) Analysis Request

We are observing a transceiver power-up calibration time of approximately 353 ms on a Cyclone 10 GX device (10CX220YF780I6G) using all 12 transceivers.

The total system startup requirement is 250 ms (configuration + calibration + system boot constraints), and the calibration phase alone is currently a limiting factor.

According to the Cyclone 10 GX Transceiver PHY User Guide, calibration is performed automatically during device configuration via the PreSICE engine and is dependent on reference clock stability, PLL lock conditions, and reset controller sequencing.

The documentation does not specify a deterministic calibration duration.

Please can you provide clarification on the following points:

  • Is a ~353 ms calibration time expected behavior for a design using all 12 transceivers on this device family?
  • Is transceiver calibration executed sequentially across multiple quads, or is full parallel calibration supported for all active transceiver banks in Cyclone 10 GX?
  • Are there any recommended design practices (reset controller configuration, PLL topology, clocking architecture) that can reduce power-up calibration latency?
  • Can calibration duration be significantly impacted by reference clock stabilization time or internal wait states prior to PreSICE execution?

The goal is to determine whether the observed latency is inherent to the device architecture or if it can be optimized at system level.

2 Replies

  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor

    Hi,

     

    From my understanding, you have a few questions related to transceiver (XCVR) power‑up calibration on the Cyclone® 10 GX device. To make sure we’re aligned, could you please share with me how you are measuring the calibration time in your setup (for example, which signals you are monitoring and from which point to which point the time is measured)?

     

    Below are my responses to your questions:

     

    1. Is a ~353 ms calibration time expected when using all 12 transceivers on this device family?

    Based on available documentation, there is no specific, fixed calibration-time specification for Cyclone 10 GX devices. As stated in the Cyclone 10 GX Transceiver User Guide, calibration duration can vary by device.

    Assuming:

    • All clocks are stable & free-running prior device configuration, within specification, and
    • All *_cal_busy signals deassert cleanly,

    a ~353 ms calibration time would generally be considered expected behavior, rather than an anomaly.

     

    2. Is transceiver calibration executed sequentially across multiple quads, or is full parallel calibration supported?

    I do not have explicit visibility into whether calibration is fully parallel or strictly sequential across quads. However, based on general understanding, the calibration process appears to be a combination of parallel and sequential operations across different internal blocks.

    As a result, designs using fewer channels (for example, 1 or 6 channels) would be expected to have shorter overall calibration times compared to designs using all 12 channels.

     

    3. Are there recommended design practices to reduce power‑up calibration latency?

    If you are currently using CLKUSR at 100 MHz, you may try increasing it to 125 MHz to see whether it helps reduce calibration time.

    In addition, please ensure that:

    • CLKUSR and all reference clocks are stable and free‑running before FPGA configuration begins

     

    Please let me know if you have any follow-up questions. I’ll be happy to assist further.

    Thank you.

  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor

    Hi,

     

    Thank you for filing this case and sharing the details. I appreciate your patience. Please allow me some time to review the information, and I’ll get back to you as soon as possible.