Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

using spi core

I want to use the spi core for adc peripheral AD9253. It has bidirectional SDIO. but spi core in nios has miso and mosi. so how do i tackle this. i want to read and write to the adc registers.
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

--- Quote Start ---

A simple solution is driving SDIO in open collector mode using a tristate i/o buffer and a pull-up resistor.

MOSI is connected to the active low buffer enable port, while the i/o buffer input is hardwired to gnd.

MISO is connected to the same i/o pin.

This way you simply put ones in the spi tx register for the bits you are supposed to receive.

--- Quote End ---

Hello, sherindeena!

Did You try to make it this way?

Here are another replies to this question:

http://www.alteraforum.com/forum/showthread.php?t=26838

http://www.alteraforum.com/forum/showthread.php?t=38228

Which one is correct?

I am interested because I am about to make the similar connection.