HDLC Setup

I’m trying to configure a serial port for HDLC communication - interrupt driven. The HW Ref Guide doesn’t guide me. I’ve set up the port to use hdlc mode configuring in a numerous of ways but the FIFO does not seem to shift out any bits at all just throwing it away since the time from the first byte to the last byte accepted is zero. Resetting nothing but the ctrl_b mode to UART and the birate register to X16 with the same bitrate gives me the expected time from first to last byte to the out-fifo, also setting local loopback works fine with the UART mode. What have I missed ?

Have you seen the readme file in nahdlcapp? It should have the details you’re looking for.