Missing data from real bus trace

Question

In slave mode, while reading data from “ftdi_slave_read” it is giving a data frame which is not transmitted from the opposite end. Below data is transmitted from the opposite end(line 7)

I feel that it taking from the FTDI chip buffer. Is there any steps or function to clear buffer data of FTDI hardware?

Answer

Scope/analyzer shows an extra nibble (one byte + a nibble) in every frame.  The driver’s text file report shows only the first byte and doesn’t show the extra nibble of the frame.  There could be a setting in the analyzer/scope which shows the extra nibble that confuses you.