SPI Protocol Analyzer mis-interprets data at high data rates

[Wayne Contello]

I am using Waveforms 3.21.13 on macOS 14.1.

 

I think the SPI protocol analyzer incorrectly interprets data when the data rate is high.

SPI clock Freq: 6.25Mhz

Waveforms Sample rate: 100MHz.

 

 

When the SPI clock rate is: 3 MHz (decoding is correct):

 

When the SPI clock rate is 6MHz (decoding is incorrect)

 

 

 

 

 

The device I'm debugging receives the correct data, So I think the problem is in the way Waveforms (or the Analog Discovery 2) is sampling the data.  I do not have a source terminated clock on the uC so maybe there is ringing or reflections.  It also looks there are "extra" clocks somewhere because the aligmnment of the interpreter is off compared with spi clock groupings..

 

I can share a capture if it is helpful.

 

Thanks,

Wayne

 

[attila]

Hi @Wayne Contello

Notice the samples lost warning.
The record uses data streaming which has limitation in average toggle rate.
You could try reducing the sample Rate, the Samples captured or use the default Repeated Mode.