MPC5748G dev board: Cannot get more than 230400 baud rate for UART from microUSB port

[pmrlcbtcphtzjdq]

Hallo!
I am trying to implement an application that uses UART baud rate of 460800. This baud rate is supported by the MPC5748G chip however, I cannot get it working on the microUSB port - precisely speaking on the LINFlexD_2 instance that uses PC[8] and PC[9].

I tried using other pins (other instaces of LINFlex interface) and this baud rate generally works. Only the LINFlexD_2 doesn't support this speed. And I have to get this speed working on the micorUSB port ( PC[8] and PC[9] ).

Any ideas why it is designed this way, and how to solve this problem?

@lukaszadrapa 

[PetrS]

Hi,

Most probably the issue is that a baudrate is not set similarly on both the K20 and MPC5748G.
Try to measure actual baudrate generated by K20, measure MPC5748G's PC9 pin. If you set the LINFBRR and LINIBRR of the MPC5748G in the way you get a baudrate as close as possible to measured one, then you should be able to communicate properly.
I think K20 actually gives 500000kbps. Lets try LINFBRR=0 and LINIBRR=10, assuming LINFlexD_2's baud clock is 80Mhz.

BR, Petr