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snehal_p's avatar
snehal_p
Icon for Contributor rankContributor
3 years ago
Solved

Increase frequency of HPSGPIO

Hello, How can we increase the HPS gpio frequency? I'm driving Shift register CD4094 from HPS. Can I increase the frequency of clk generated from hps to drive cd4094? what is the maximum frequenc...
  • aikeu's avatar
    aikeu
    3 years ago

    Hi snehal_p,


    I try to check further regarding the gpio limitation on arm cortex a9 for the HPS.

    It shows that:

    "The PL061 PrimeCell General Purpose Input/Output (GPIO) is an AMBA compliant SoC peripheral that is developed, tested, and licensed by ARM Limited. Use the GPIO to generate or detect low frequency signals (less than 1MHz)."

    https://developer.arm.com/documentation/dui0440/b/programmer-s-reference/general-purpose-input-output--gpio

    It seems that the frequency you are capable of generating also meet around that range due to the limitation of the GPIO regardless of the instruction cycles which involves in the gpio toggling operation.


    Thanks.

    Regards,

    Aik Eu


aikeu's avatar
aikeu
Icon for Regular Contributor rankRegular Contributor
3 years ago

Hi snehal_p,


Are you using the PIO IP on the FPGA side to drive the clock of the shift register? if so then can consider increase 50 Mhz and see if it helps and do not affect the overal system design clock synchronization.

The HPS processor operating frequency for Cyclone V is 925 Mhz and can check in platform designer on the HPS IP block under Output clocks.


Thanks.

Regards,

Aik Eu


snehal_p's avatar
snehal_p
Icon for Contributor rankContributor
3 years ago

Hello Aik Eu,

No, we are not using PIO IP, actually the clk is connected to the hpsgpio on the board.

Is there any way we can increase the clock frequency to drive the shift register to 10-14MHz.

What is the maximum frequency that could be achieved on hpsgpio of my system clock is 50 Mhz.

Thanks,

snehal_p