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Altera_Forum's avatar
Altera_Forum
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14 years ago

UART Pin Assignment

Hy there, another newbie question.

I made applied UART function into my system (created in Quartus II).

My question is it needed to apply any pin assignment to this UART in Quartus II? (since i dont see any input/ouput by UART, so i didnt apply them in my past experiment).

Any apply will be appreciated.

Thank you,

Yuyex :o

10 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    I think if you have uart in SOPC builder.

    your SOPC builder must have UART input/output pins

    which don't have to be connected to outside of FPGA.

    but why you set UART-IP in your system?
  • Altera_Forum's avatar
    Altera_Forum
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    Thank you for your reply Akira,

    I got "rxd_to_the_uart" and "txd_from_the_uart" pins.

    From your reply, I assumed it isn't necessary to be assigned to any of my DE0 board?

    Thank you,

    Yuyex:o
  • Altera_Forum's avatar
    Altera_Forum
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    According to your figure.

    You created your SOPC by your self.

    So,why you attached uart which you don't even know how to use.

    Anyway, you don't have to use uart.

    DE0 board doesn't have RS-232C port.

    Unless you want to use uart as a practice, you can connect tx port to rx port.

    Have a good time with your board.
  • Altera_Forum's avatar
    Altera_Forum
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    Thank you for your reply again Akira,

    Yes , i did an experiment based on a book which teaching me how to build an SOPC.

    This book is using EP1C20F400C7 of Cyclone Family, and I am using EP3C16F484C6 of Cyclone III family (DE0).

    The project which is given by the CD of the book ALREADY HAVE their pin assignments, including the unused pins(for EP1C20F400C7 of Cyclone Family of course). Since i have to change the device, all of the pin assignment will be deleted. So i am a bit confused if RS232 should be assigned as output or input and where to be assigned?

    Yes, DE0 board doesnt have any RS-232C but it has RS-232 port, right?

    Thank you,

    Yuyex:o
  • Altera_Forum's avatar
    Altera_Forum
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    damn, I didn't know that.

    I'm sorry.

    yes you can use RS-232C.

    can you solder?

    you can connect those pins to D-SUB9 connecter.

    pin No.2 on D-SUB9 as RXD

    pin No.3 on D-SUB9 as TXD

    Pin No.5 on D-SUB9 as GND

    leave rest of pins.

    thanks Yuyex.

    I have been helped by you too.

    so you want to know how to assign RXD,TXD.

    I will reply again after this.
  • Altera_Forum's avatar
    Altera_Forum
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    1.assign pins.

    double click somewhere on block-diagram field.

    from library,[primitives] -> [pin] ->[input]

    also [primitives] -> [pin] ->[output]

    2. rename pins

    connect those pins to your SOPC builder.

    right click those pins and select [properties] you can rename it as RXD / TXD.

    3.compile once.

    [Processing] -> [Start Compilation]

    4.assignment.

    [Assignments] -> [Pin Planer]

    you can assign ...

    TXD to U22.

    RXD to U21.

    5.compile again.

    [Processing] -> [Start Compilation]

    is that what you wanted?
  • Altera_Forum's avatar
    Altera_Forum
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    Thank you for your reply Akira,

    I think I got your point on pin assignment,.

    "can you solder?" << Yes :o

    I have another simple(newbie) question, how can the system (SOPC) can communicate with my board ? by using this RS232?

    My problem is I dont know if it's necessary to use this RS232 function on my SOPC. Since I am just learning to build an SOPC, so I was just following the my reference book(which is Chinese book, damn ! it made me headache by just reading it since my Chinese is worse than my English :eek:)

    After I surfing on the internet, i think I dont need this UART/RS232 if my objective is just to communicate between SOPC and my board.

    Looking forward to your guidance:o.

    Thank you,

    Yuyex :o

  • Altera_Forum's avatar
    Altera_Forum
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    Hello Guys,

    I got a picture which maybe an answer to my own question.

    From the picture, I can conclude that i dont need to assign another output/input in Quartus II [Pin Assignment] for this JTAG UART interface (which is created in my system by SOPC builder of Quartus II).

    Please correct me if i am wrong.

    Any reply will be appreciated,

    Yuyex:o
  • Altera_Forum's avatar
    Altera_Forum
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    Thank you for your help Akira ..

    Appreciate it so much ..

    Hope to see you again in my next questions :o

    Thank you,

    Yuyex:o