The Water Cooler

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  • 1.  BCM58305 - Problem with GPIO SPEED

    Posted Feb 14, 2024 10:29 AM

    We have a problem with GPIO response time in BCM58305 where we are just setting the GPIO output register in a **** loop that gives results as 3.3Mhz waveform (on physical GPIO) - in such conditions we are not running any other tasks. In the infinite loop software just writes value to the ASIU_SGP_DATA_OUT_3 register.

    #define HVAR(object, addr)   *(volatile object *)(addr)
    3,33 MHz

    Other Broadcom processor resulting output wave on the BCM2835 of 22.7Mhz, the BCM2836 reaches 41.7Mhz

    We are currently using  ARM926EJ-S with clock speed  384 Mhz gives GPIO results  9.5Mhz (3 times faster than BCM58303 with clock speed  1200 Mhz).

    Here are some BCM58305 speed sensitive register values


    and (we thing so some IDM wrappers registers)


    BCM58305 has proper speed in execution code and using both CACHES L1 and L2

    GP Timers (SP805) measure proper delay - what confirms proper 100Mhz peripheral clock also used to GPIO

    GPIO speed measure after Soc leaving factory ROM (before start running OS) is a little slower (because CACHES are not enabled Yet) reaches speed 1.88Mhz 

    We would like to try to access GPIO via ACP (using the 33rd address bit).

    We check datasheet manual 5830X-DS210.pdf in section "When programmers set field Bypass_CT to 1 and Coherant_Transation (CT) to 1, the IDM wrapper unconditionally tags the peripheral's memory address as ACP accesses."

    Questions : Which one  IDM wrappers are responsible for GPIO access using  ACP ? Please provide an address or exact register name ?

    or what are other solutions to increase GPIO speed in BCM58305.

  • 2.  RE: BCM58305 - Problem with GPIO SPEED

    Broadcom Employee
    Posted Feb 14, 2024 10:41 AM

    Hi @Sebastian Zur,

    We do not have a support community for this product. Please use our support center to reach the right support channel for your product.
    Also, You may visit the product page BCM5830X Family and click on "Request Info"

    Thank you,

    Ravi Kumar
    Customer Care Community Admin
    Broadcom Software

  • 3.  RE: BCM58305 - Problem with GPIO SPEED

    Posted Feb 14, 2024 10:50 AM
    Edited by Ravi_ Feb 14, 2024 10:57 AM

    Thank you very much for your answer.

    Before I posted my message I have tried other channels but without any


    Edited by @Ravi - Removed the phone number, email ID, and other sensitive data from the public post to prevent it from being scraped.​