To show the limitations of the 2 UART ports on J2.
Refer to J2 pin definition in user munual, we can see there are 2 UART ports on it.
In most designs, UART function is built in super IO or other UART controllers.
But the 2 UART ports on MIC-3332 J2 are connected to PCH, and have the following limitations.
In PCH, the PCH UART controller is directly connected to the PCI bus, which means it is a PCI device, and need a driver to implement this function.
But Intel don't provide the driver for Windows, so these 2 ports cannot be showed in device manager default. If need to use these UART ports, users need to develop driver by themselves.
For Linux, kernel driver "intel-lpss" and kernel module "intel-lpss-pci" are needed, but only few kernel versions have these built-in drivers. Moreover, until now the RS-422/485 function still cannot work normally.
So based on the above reasons, PM determined to remove these 2 UART ports from J2. Datasheet and user manual will be updated later.