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S32 LPSPI0 PCS[2] not active

Question asked by gellertbalogh on Feb 8, 2018
Latest reply on Feb 20, 2018 by gellertbalogh

Hello folks,

I need to read out two ADC’s using the LPSPI0 module in the S32k144 controller. The ADC’s ship selects are connected to LPSPI_PCS0 and LPSPI_PCS2 respectively. While the 1st one works like a charm, I have difficulties with the latter. If the pin is set as a GPIO I can measure both High and Low level signals at the 2nd ADC’s chip select pin – thus output stage, trace, soldering, etc. should be fine.

However, if the pin is configured as PCS2 it remains low permanently – despite of the Active Low Setting.

 

In order to be sure, that the code works correctly I tried to use PCS1 instead of PCS2. So the only difference in the code is basically two constants at the initialization: one for the pin itself and one for the SPI module (whichPcs).

 

In a perfect world I could just stay with PCS1. Unfortunately though, we need that particular pin for PWM out. Furthermore this is the 64pin variant, I have no access to LPSPI_PCS3.

Can this phenomenon caused by a chip level error? 

 

(The ADC I’m using is ADC101S1 from TI. It needs 16 clk pulses to transmit data, and has no data input other than CS)

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