I am currently working on a custom board design using the MM8108 module. The datasheet notes that the GPIOs can be configured for alternate functions such as SPI master, I²C master, PWM, and UART. However, I haven’t been able to find any documentation that specifies which GPIO pins support which functions. Can each pin be configured for any of these peripherals, or are certain functions limited to specific pins within the GPIO group?
Additionally, is there a recommended method or tool for configuring the pin functions?
Hi Thomas, I had a look at the MM8108-MF15457 datasheet, I’m pretty sure I found the bit that you’re referencing, but unfortunately those GPIO pins aren’t currently used and cannot be configured by users.
[3] GPIOs 0 to 10 may provide alternative functions, including SPI master, I2C master, PWM, and UART. This functionality necessitates custom software, which Morse Micro can develop upon request. For further details, please contact Morse Micro
This definitely leaves some leeway for interpretation, that “may provide” is doing some heavy lifting, but essentially what this means is that those GPIOs are there in case future firmware revisions add functionality that utilises additional pins on the chip.
Not having these would mean that a new module revision would need to be spun up to break out those pins on the chip to support the newer firmware, users would need to make sure they have the right revision of the module for the new features, and suppliers suddenly have a new product skew.
