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Veerappan's avatar
Veerappan
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11 months ago

How to use HPS internal clock in Agilex 7 SOC

Hi, How to use HPS internal oscillator as a source for both main and peripheral PLL.   I tried by choosing the Internal oscillator in a general configuration in Platform Designer device->...
Fpga Devkit
KianHinT_altera's avatar
KianHinT_altera
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10 months ago

Hi Veerappan,

Sorry for the delay, was discussing your 3 forum issues with our team. Could you give more details like what other changes in your configuration and the steps you use to build, program and read back the register, additional logs /design files would be helpful?

I will try to see whether I could source an Agilex 7 SOC on my side to replicate based on your configuration.

Thanks

Regards

Kian

Veerappan's avatar
Veerappan
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10 months ago

Hi khtan,

I am using ARMDS to program, debug the uboot and read register value. Actually My question is how to configure HPS internal oscillator as source for both main and peripheral PLL.

Thanks,

Regards,

Veerappan P.

  • KianHinT_altera's avatar
    KianHinT_altera
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    9 months ago

    Hi Veerappan,

    Sorry for the hold up, I've checked with our embedded team and also factory guy on this regarding the documentation mentioning about internal OSC usage and also testing out the Quartus

    Internal OSC is not available as source for both main and peripheral PLL.

    The confusion is actually because of the documentation statement that mentioned about the inputs to PLL but on the note below, it does mentioned that Internal OSC cannot be used under normal circumstances. Internal OSC is meant for bring up HPS, after bring up HPS will switch to HPS_OSC_CLK

    even though you configured at Device and pin options to use internal OSC

    but in HPS QSYS, main PLL and peripheral PLL input clocks (under internal clocks and output clocks tab) are limited to external OSC or FPGA to HPS free clock(if enabled) only

    enable FPGA-to-HPS free clock (input clocks tab)

    Hope that clears up the OSC issue not locking and still remaining default to External OSC when reading the register back.

    Thanks and sorry for the delay in getting back on this.

    Regards

    Kian