LPC55S69 FLEXCOMM3 RX not working

[nxf51434]

As the title, customer test the uart3(flexcomm3) on EVK and found the uart3 can send data successfully but can't receive data. They test other uarts like uart1 and uart7, all can work properly. @Logiase.song

[Logiase · Accepted solution]

connect P1 solve this problem.

The level translator change the pull level of P0_3 (rx). 

[xiangjun_rong]

Hi,

I see your phenomenon, close P1, the BRIDGE_OE pin will be high, U6 and U3 will be disabled, the pins of U3 and U6 will be float, if you connect the external uart transmit signal to FC3_RXD pin(PIO0_3), in detail  pin 3 of P20, it will function.

BR

XiangJun Rong