I'm having difficulties to understand I/O pad configuration details. The reference manual (rev 2) is not clear on that. Documentation is spread across two chapters: Chapter 10 - IOMUX Controller (IOMUXC), and Chapter 11 - General Purpose Input/Output (GPIO).
Q1: IOMUXC_SW_PAD_CTL_* register fields PUE, PKE and PUS. How do these bits correlate? Is the following interpretation correct?
PKE=0 PUE=* PUS=* - output is plain, no keeper, no pullup/pulldown
PKE=1 PUE=0 PUS=* - keeper is active, no pullup/pulldown
PKE=1 PUE=1 PUS=* - no keeper, pullup/pulldown active according to PUS
Q2: OMUXC_SW_PAD_CTL_* register fields SPEED and SRE. How do these settings correlate? According to Figure 11-3 both settings configure the output driver. The reference manual does not have more details. The data sheet refers to slew rate settings only.