We have designed a custom board using the RT1064 that mostly functions as expected. In our design, we are using RT1064 LPUARTs 4, 6, and 8, which are connected to header pins.
A problem we are observing is that when we reset the processor with devices connected to all the LPUART header pins, it halts and does not boot up. However, if we only connect a single device to one out of the three LPUARTs (does not matter which one), the processor boots up without any problems. And then upon successful boot-up, all LPUARTs function normally with any combination of devices attached.
Any ideas as to what could cause this from either the hardware or software side?