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SPI - spikes on the MOSI line between frames

sjpatel19922
Associate III
Posted on May 03, 2017 at 18:05

Hi, I am using the 

SPC570S40E1 microcontroller. When looking at the MOSI line on the scope, I am seeing spikes right around the end of a frame even when transmitting all zeros. The device I am trying to communicate with requires a 40 bit message. To achieve that, I am sending 16,16 and 8 bit frames. 

There is one spike at beginning of the second frame and another at the beginning of the third frame.

Also, regarding the Fast Continuous PC mode, which allows masking the Tasc and Tcsc delays, is there a way to enable the masking of delays without  also enabling parity bit transmission.

Thanks

Update: I don't see any spikes if I enable continuous clock, but I am still looking for a solution without having to do that. I tried lowering the baud rate and adjusting the delays( Tasc and Tcsc), but that didn't work.

#spi
1 REPLY 1
Erwan YVIN
ST Employee
Posted on June 20, 2017 at 15:19

Same issue as

https://community.st.com/0D50X00009XkehiSAB