In order to get the SPI4 module working on a TMS570LS3137PGE (144-pin QFP), I was required to set PINMMR23[24] to 0 in the IOMM control registers. This activates the multiplexed pin 31 (SPI4SOMI) as an input..
The muxInit() generated by HALCoGen erroneously puts the PINMMR23 register to the standard value 0x01010101, regardless of the user specified settings. And when reading section 4.3.2: control of multiplexed input on page 256 in the reference manual, it should indeed not be necessary to clear this bit. From my experience however, I can tell that this is necessary: activating a multiplexed pin as an output, does not automatically activate it as an input to that module.
I thought this might be something good to know and to correct in the next version of the reference manual.
