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Altera_Forum's avatar
Altera_Forum
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13 years ago

Using SPI Without MISO

Hi All

I'm using a Nios II as a SPI master and connecting to a DAC (LT1452) slave.

The DAC has no returning MISO line, is it still possible to use the Altera SPI core?

I was assuming I could just connect the MISO to the MOSI line (since SPI needs some data to receive) and ignore the returned data.

2 Replies

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

    In SPI, it shifts data out while receiving data. If there is no receiving data, you should be able to just tie it off. I've used microcontrollers with SPI slaves that had no MISO and just tied that high.

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

    You can indeed connect MISO to MOSI, but it's even better to connect it to a constant signal, either '0' or '1', and then the receiving shift register will be optimized away.