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TMS570LS0232: Can EXTCLKIN be a clock source of GCLK?

Remony
Expert 1560 points
Part Number: TMS570LS0232
Other Parts Discussed in Thread: HALCOGEN

Standard source includes EXTERNL1 in HalCoGen.

But all of Clk Domains are 0 Hz when EXTERNAL1 is selected as the Standard Src.

Can EXTCLKIN be a clock source of GCLK?

  • 0
    TI__Mastermind 49120 points
    Hello,

    You can certainly configure an external clock input to be the main source for the chosen clock domains. However, you do need to provide a clock signal as input to this EXTCLKIN pin for this clock to be used.

    Are you driving a clock signal into the EXTCLKIN pin (pin # 10, GIOA[5]/EXTCLKIN)?

    Regards,
    Sunil
  • 0 in reply to Sunil Oak
    Expert 1560 points
    Yes, EXTCLKIN pin is connected to 30MHz oscillator.
    GIOA[5] set as EXTCLKIN.
  • 0 in reply to Remony
    TI__Mastermind 49120 points

    Remony,

    Does the 30MHz oscillator meet the maximum ViL (0.8V) and minimum ViH (2.0V) specifications of a TTL input signal? The electrical specifications for the external clock input are missing from the TMS570LS0x32 datasheet. We will include these in the next update.

    Also, you need to enable the External clock input as a clock source on the "Clk Source" tab in HALCoGen.

    Regards,
    Sunil

  • 0 in reply to Sunil Oak
    Expert 1560 points

    Sunil Oak,

    Yes, It does. It supplies 3.3V square wave form.
    I enable the external clock input as a clock source on the "Clk Source" tab in HALCoGen.
    But "Clk Domains" in HALCoGen are zero.
    I don't know why "Clk Domains" aren't apply the External clock

    I'm going to change clock pin from the EXTCLKIN to the OSCIN.
    The OSCIN has input range from 5MHz to 20MHz. So I need to change frequency of oscillator.
    Is it OK?

  • 0 in reply to Remony
    TI__Mastermind 49120 points
    Remony,

    I see the issue you reported on the HALCoGen display. Do you also see the 0MHz on the actual silicon, or do you get the proper 30MHz clock for the CPU clock domain?

    Regards,
    Sunil
  • 0 in reply to Sunil Oak
    Expert 1560 points

    I can't test on the silicon. I have not made the board yet.
    Thanks.