RX Buffer functional coverage
Implement functional coverage for RX FIFO:
At least following cases should be covered:
- Buffer empty
- Buffer full
- Buffer overflow
- Buffer read-write at the same time
- Buffer read-write just after/before each other (one clock cycle)
- Data overrun occurs.
- Read by burst (memory pointer muxed).
- Storing SOF timestamp (in FSM).
- Storing EOF timestamp (in FSM).
- Storing RTR frame
- Storing Frame with 1, 2, 3 and 16 memory words for data.
- Stashing frame based on memory full.
- Stashing frame based on error frame (rec_abort).
- Buffer reset by SW.