Forum Discussion

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

SPI Slave bug?

Has anybody used the SPI core as a slave device in a NIOS II implementation? If so, have you had relatively frequent data errors? There is no HAL for the SPI as slave, so I'm just using th...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Recently upgraded to 91sp1 but still the same. As master everthing is flawless as slave everthing seems to be random.

I just noticed that the signal from slave also toggles sometimes at the wrong clock edges.

On the screenshot:

yellow:clock

blue: slave select

green: MISO (here is the problem)

red: MOSI

The settings ( Clock Polarity and Clock Phase ) in SOPC-Builder are both set to 1. So the data should only toggle on negative clock edges.

Does anyone of you got the SPI Slave running without errors? Perhaps someone can send me his code?!

Thanks.