BSOM PWM Documentation confusion

There seems to be a bit of confusion with the Datasheet and the Reference documentation.

On the BSOM5 Datasheet the Peripherals and Gpio section details 7(max) PWM outputs, but the Pin Description section only shows 4.
Then the Reference documentation details 7 (D4, D5, D7, A0, A1, A6, and A7) in one part and 8 in another part of the same section (group2: A0, A1, A6, and A7, group1: D4, D5, and D6 , group0: D7)

So what is the actual supported PWM on a B5?

It’s 8. The reference list of groups was correct. I fixed the heading above it.

On the Boron SoM, pins D4, D5, D6, D7, A0, A1, A6, and A7 can be used for PWM. Pins are assigned a PWM group. Each group must share the same frequency and resolution, but individual pins in the group can have a different duty cycle.

  • Group 2: Pins A0, A1, A6, and A7.
  • Group 1: Pins D4, D5, and D6.
  • Group 0: Pin D7 and the RGB LED. This must use the default resolution of 8 bits (0-255) and frequency of 500 Hz.

The datasheets now list 8 in the two places at the top.

However, the reason that are only 4 pins named in the pin description is those are the SoM pin names, not the complete lists of functions for each pin. The four PWMx pins are the pins across all SoMs that are likely to include the PWM feature. This is a little confusing because there are only the B Series B4xx and B5xx SoMs now, but there will be others in the future, possibly with a different MCU.

Other pins support PWM on the B4xx and B5xx, but future SoMs might not have that feature. There are also additional analog pins on the B4xx and B5xx, and additional GPIO on reserved pins. You can use those pins, but it’s possible that the extra features might change in future SoMs.