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Altera_Forum's avatar
Altera_Forum
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19 years ago

RS232 DE2 board

Hi all,

I'm working on a summer project and am trying to use the RS232 connection to connect the DE2 altera board to a hyperterminal on the computer to allow display information from the board.

In the specs, they state that there are two pins, receive and transmit, for the UART which is to be used for the RS232. I connected these respectively to the internal signals but am still not getting a display.

Is anyone familiar with using this interface and could maybe help me find what I'm doing wrong/missing here.

Thank you

Paul

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    19 years ago

    Hi

    I hope you have the connections right.

    i.e to say RX of DE2 -> TX of PC

    TX of DE2 -> RX of PC

    Secondly, Is your hyperterminal settings is

    same as your design? i.e Baud rate,data bits,Stop bit,Parity etc?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    19 years ago

    Hi Paul,

    what kind of project do you have? HDL-code only or SOPC Builder project maybe with Nios processor?

    If you have a nios processor system, you could search the Nios Forum (General Discussion and General Software Forum) for "uart" and "rs232", because there are plenty of posts according to this topic with good hints.

    A simple C-function to send characters is this one:

    void UART1_T(unsigned char ch)

    {

    while((IORD_ALTERA_AVALON_UART_STATUS(UART_BASE) & 0x040) != 0x040)

    { ;}

    IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE,ch);

    }

    You can find it in the thread "Need help for my RS232 in NIOS II" in the "General Software Forum" of the Nios Forum.

    And did you check check the Volume V, section II "Communication Peripherals", chapter 6 "UART Core with Avalon Interface" of the Quartus II Handbook (http://www.altera.com/literature/quartus2/lit-qts-peripherals.jsp) already?

    Hope that helps :)