• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 98 subscribers
  • Views 296 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM6548: Acess to UART0..UART2 not possible

42Bastian
Expert 1430 points
Part Number: AM6548

I am in  "NO BOOT" mode debugging the CR5 and strangely cannot access to UART0..UART2.

Any other peripherals are accessible but if I want to dump the UARTx registers with the debugger, the system hangs.

Is there anything special to do? I check PDK but cannot see a hint.

Cheers

42Bastian

  • 0
    TI__Mastermind 42135 points

    Hi,

    I am able to access registers for UART0 - UART2 from R5, without any issues.

    Can you please provide the following details:

    1) What application are you running on R5?
    2) Is there anything running on A53 core?
    3) Can you please share the screenshot of error you are facing?

    Regards,
    Parth

  • 0 in reply to Parth Nagpal
    Expert 1430 points

    "NO BOOT" mode => A53 off, CR5 in lock-step mode (set by Trace32), no software running so far.

    CR5 accesses to the UART memory returns 0 no matter where I read.

    Debugger access causes system crash.

    Does the GEL script anything to enable the UARTs?

  • 0 in reply to Parth Nagpal
    Expert 1430 points

    I did more checks, and any other peripheral which is connected to the same clocks as UART0..2 works just fine.

    Could it be that the boot-rom disables access to the UART even in "no boot" mode?

    Do I need to run the DMSC firmware to enable UART0..2.

    If I boot via u-boot these UARTs are working, but CR5 is switched off, and I did not succeed to re-enable it with the debugger.

  • 0 in reply to 42Bastian
    TI__Mastermind 42135 points

    Hi,

    42Bastian said:
    NO BOOT" mode => A53 off, CR5 in lock-step mode (set by Trace32), no software running so far.

    You might be facing the issue because main domain in not powered up. UART0 - UART2 lies in the MAIN domain and if you just connect R5, it won't initialize the MAIN domain.

    You'll need to initialize the MAIN domain, either by using the GEL scripts or by loading some application on A53 using SBL in order to access peripheral registers from MAIN domain.

    Regards,
    Parth

  • 0 in reply to Parth Nagpal
    Expert 1430 points

    But i2c and gpio is also in the MAIN domain and this are working.

    As I wrote, if I boot with u-boot (which runs on A53), the UARTs are working, but CR5 is switched of, and I cannot switch it on with the debugger.

    What is different from UART to I2C or other peripherals in MAIN domain?

  • 0 in reply to Parth Nagpal
    Expert 1430 points

    Arg, the boot mode settings on the custom board where not related to the official boot mode settings. Thus what I thought is "sleep no boot" was actually eMMC boot.

    I found a different setting which is "no boot".