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Altera_Forum's avatar
Altera_Forum
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14 years ago

DE2-70 and I2C

Dear Sir,

If I want to design an I2C port on the FPGA, like DE2-70, do I need

an I2C bus extender? How to add it onto the DE2-70? I've one

example design from the I2C bus extender, P82B96 from NXP.

It shows it needs a pair of chips at both side of the ribbon I/O cable.

Suppose, it needs to add an interface card on the FPGA before

connecting the cable. Are there any easier way to handle the problem?

Thank you!

Regards,

Peter Chang

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi,

    i have used a free i2c core from www.opencores.org (http://www.opencores.org)

    It is an i2c master core with wishbone interface.

    You can easily connect it to the avalon mm bus to use this core with the nios processor.

    The two lines "SDA" and "SCL" from the I2C Core are bidirectional data lines.

    You only need a pull-up resistor (4,7k .. 10k) on each line.

    "SDA" and "SCL" are simple IO-Pins from your FPGA. You don't need a bus extender.

    If your FPGA IO's and the other I2C Device are on the same voltage level e.g. 3,3V

    you can connect the other I2C devices direct to your FPGA.

    Otherwise you need an I2C Level Shifter between the FPGA and I2C Device.

    Hope that i could help you.

    Nicolas
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Dear Nicolas,

    Thanks for your sharing. Let me explain more about my case.

    The problem I met is when I'm using an I2C interface between

    the DE2-70 and external board via a falt ribbon cable. In the case,

    it may need an extender, because the signals, SDA and SCL are

    not as stable as that I expected. Do you think so? Thank you!

    Regards,

    Peter Chang:confused:
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    13 years ago

    Hi all,

    I'm working on the adxl345 on DE0-nano board for my university project,

    and I have some problem with My nios program in eclipse IDE.

    I've seen your post in the site about running this program.

    If it is possible ,Please help me how can I run this core into my design if you have done it.

    I'm using Quartus 11.1 and I will appreciating if you send me the programs.

    when I run the program It does not even start the transmitting and I suspect my sw.tcl or one other file is corrupted by the changes that I did to those files, so

    I will appreciating if you send to me the project files.

    farshid_mfc[at]yahoo.com