Depending on which VLEN mode is used, attempting a variable length transfer with length 0 or 1 can lead to
erroneous behavior by the DMA. The failing conditions will not occur naturally in an application as they do not
transfer useful data, but may occur as the result of an error condition at the source of the DMA transfer. The
DMA is generally set up with variable transfer length to transfer packets that come in over USART or RF. If
there is an error in the medium, these packets may be malformatted. If they for example contain a length byte
of 0, using the DMA to transfer those packets automatically without taking the described precautions may lead
to a buffer overrun. The two VLEN modes that are affected are VLEN values 001 and 010. VLEN values 000,
011 and 100 work without restrictions.?