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Altera_Forum's avatar
Altera_Forum
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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

Any news here?

I'm experiencing similar problems. My Cyclone III is configured as Slave another controller as Master.

For testing I set up the master to send 0x5555 and the slave to send 0xffff all the time. As I did not receive the right values in both direction I took a look at the bus. You may want to have a look at the screenshots:

yellow - clock

green - slave select

blue - MOSI

red - MISO

The data the code of the master shows are exactly the same I can see on an oscilloscope. So there cant be a problem on masters side.

The data I want to send from slave's side varies on the bus (as shown on the screenshots). And the data I receive on slave's side seems to be totally random. I've never received valid data in slave.

I've not tried yet to interchange master-slave to see if this is caused by a faulty slave driver. I anyway prefer it to have it the way it is and to solve the problems.

Any hints are appreciated.

Kind Regards.