Details:

The RXEMPTY flag may not be auto-cleared after a CPU or DMA read when the following conditions are met:

• The TXFULL flag of the latest buffer that the sequencer read out of transmit RAM for the currently active transfer group is 0
• A higher-priority transfer group interrupts the current transfer group and the sequencer starts to read the first buffer of the new transfer group from the transmit RAM
• Simultaneously, the Host (CPU/DMA) is reading out a receive RAM location that contains valid received data from the previous transfers

Workaround(s):

If at all possible, avoid transfer groups interrupting one another. If dummy buffers are used in lower-priority transfer groups, select the appropriate "BUFMODE" for them (like, SKIP/DISABLED) unless, there is a specific need to use the "SUSPEND" mode.