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)