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Altera_Forum's avatar
Altera_Forum
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14 years ago

avalon fifoed uart - problem with baudrate setting

Hi,

I am setting the baudrate as 115200 but the actual baudrtae looks to be 9600. any ideas?

i am trying to add printf to check what is happening in altera_uart.c with pr_err in altera_uart_set_termios function but not seeing any thing on the console. I have hooked the console to jtag uart.

Any ideas Please?

I am using latest 20100621 tarball without any git updates.

7 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    Do you have a CCB between your nios and your UART ?

    --- Quote End ---

    Thanks a lot for your reply. For now i don't know any thing about Clock Control Block. I will find out.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    CCB mean Clock Crossing Bridge not a Clock Control Block.

    Do you have a Clock Crossing Bridge between your Nios and you UART ?
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I had an issue with Qsys in Quartus v11.0 generating HDL with an incorrect baud rate divisor when using the "UART (RS-232 Serial Port)" component.

    This problem seems to have been fixed in v11.0 SP 1.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    CCB mean Clock Crossing Bridge not a Clock Control Block.

    Do you have a Clock Crossing Bridge between your Nios and you UART ?

    --- Quote End ---

    I understand. I do not know much here. I was informed that all devices are clocked by CPU CLOCK.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    I had an issue with Qsys in Quartus v11.0 generating HDL with an incorrect baud rate divisor when using the "UART (RS-232 Serial Port)" component.

    This problem seems to have been fixed in v11.0 SP 1.

    --- Quote End ---

    Looks like that.

    Either IP problem or some kind of initialization problem of the core in FPGA.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I have removed my comments as I found the actual problem, it is not in earlyprintk.

    The actual problem is different constant defines used at many many places of initial console code.

    Now I fixed at the right place, nios.h