• AVR Freaks

Hot!Clock failure detection on IGLOO2

Author
Akai
New Member
  • Total Posts : 2
  • Reward points : 0
  • Joined: 2020/03/16 02:27:55
  • Location: 0
  • Status: offline
2020/03/19 23:50:06 (permalink)
0

Clock failure detection on IGLOO2

Any ideas to detect failure conditions of a fabric CCC?
 
My design employs a fabric CCC to generate 100 MHz from the external clock 50 MHz. The fabric CCC is critical because all of user logic in fabric work with 100 MHz only; therefore, I would like to think the loss detector to enhance the robustness. I think the failure conditions of the fabric CCC would be detectable and can be isolated by using an internal oscillator as a secondary clock.
#1

5 Replies Related Threads

    ric
    Super Member
    • Total Posts : 26159
    • Reward points : 0
    • Joined: 2003/11/07 12:41:26
    • Location: Australia, Melbourne
    • Status: online
    Re: Clock failure detection on IGLOO2 2020/03/20 02:44:28 (permalink)
    2.33 (3)
    That is not a device made by Microchip Inc.
    I think you need to look at https://www.microsemi.com
     

    I also post at: PicForum
    Links to useful PIC information: http://picforum.ric323.co...opic.php?f=59&t=15
    NEW USERS: Posting images, links and code - workaround for restrictions.
    To get a useful answer, always state which PIC you are using!
    #2
    MBedder
    Circuit breaker
    • Total Posts : 6841
    • Reward points : 0
    • Joined: 2008/05/30 11:24:01
    • Location: Zelenograd, Russia
    • Status: offline
    Re: Clock failure detection on IGLOO2 2020/03/20 03:59:36 (permalink)
    5 (2)
    Microsemi has been acquired by Microchip long enough ago.
    #3
    sanjeevb007
    Moderator
    • Total Posts : 4
    • Reward points : 0
    • Joined: 2020/02/27 02:26:34
    • Location: 0
    • Status: offline
    Re: Clock failure detection on IGLOO2 2020/03/23 09:50:45 (permalink)
    0
    Hi Permalink,
     
    The sequence of clock switching between the primary clock (CLK1) and the secondary clock (CLK2) is explained in Microsemi_SmartFusion2_IGLOO2_Clocking_Resources_User_Guide_UG0449 section 5.4.6.1.
    https://www.microsemi.com/document-portal/doc_download/132012-ug0449-smartfusion2-and-igloo2-clocking-resources-user-guide
     
    The NGMUX provides a special switching sequence between two asynchronous clocks without generating any unwanted narrow clock pulses on the output clock. There are four NGMUX blocks in a fabric CCC and each NGMUX produces one fabric CCC output clock (GLx/Yx).
     
    Internally, there are two multiplexers to select primary and secondary clocks from the available clock sources. The primary clock source and secondary clock source to NGMUX can come from any of the following clock sources:
    • On-chip oscillators
    • FPGA fabric
    • Dedicated global I/O pads
    • 8 PLL outputs
    • GPDs outputs
     
    The primary clock and secondary clock source must generate free-running clocks without any glitches for glitch free clock switching.
    If not, the NGMUX may still produce unwanted glitches on the output clock. The requirements for a successful clock switching are:
    1. The primary and second clocks must be toggled during the switching operation.
    2. NGMUX_SEL signal must not be switched when the previous switch is still under-going and not yet completed.
     
    Hope this wll help you  detect failure conditions of a fabric CCC .
    #4
    Akai
    New Member
    • Total Posts : 2
    • Reward points : 0
    • Joined: 2020/03/16 02:27:55
    • Location: 0
    • Status: offline
    Re: Clock failure detection on IGLOO2 2020/03/23 18:18:57 (permalink)
    0
    Hello sanjeevb007,
     
    Thank you for information about NGMUX.
    I had found that feature in UG0499 and planned to use it for the clock switching.
     
    My problem will be resolved when a detector is placed to generate the NGMUX_SEL signal.
    However, I am not sure how the detector should be designed.
     
    Do you have any logic that detects anomalies of the primary clock?
     
    The primary clock of my fabric is an output of CCC.
    I could not find any built-in-self-test features of the CCC in UG0499.
     
    Best regards,
    Akai
    #5
    I30339
    New Member
    • Total Posts : 1
    • Reward points : 0
    • Joined: 2020/03/23 05:30:34
    • Location: 0
    • Status: offline
    Re: Clock failure detection on IGLOO2 2020/03/23 22:55:15 (permalink)
    0
    Hi Akai
     
    There is no ready solution as this is very implementation specific.
    Please note that NGMUX_SEL signal must not be switched when the previous switch is still under-going and not yet completed.
    Please refer to the timing diagrams provided in UG0449
     
    Regards
    Sandeep
    #6
    Jump to:
    © 2020 APG vNext Commercial Version 4.5