Functional Description
An alignment error is defined to be:
•
A frame containing an odd number of nibbles
•
Failing the Frame Check Sequence test if the final nibble is ignored
A code error is defined to be a frame which has been discarded because the port’s MRXER pin driven
with a one for at least one bit-time’s duration at any point during the frame’s reception.
Note: RFC 1757 etherStatsCRCAlignErrors Ref. 1.5 can be calculated by summing Rx Align/Code Errors
and Rx CRC errors.
14.3.2.20.1.7 Oversize Rx Frames (Offset = 18h)
The total number of oversized frames received on the port. An oversized frame is defined to be:
•
Was any data or MAC control frame which matched a unicast, broadcast or multicast address, or
matched due to promiscuous mode
•
Was greater than rx_maxlen in bytes
•
Had no CRC error, alignment error or code error
See the Rx Align/Code Errors and Rx CRC errors statistic descriptions for definitions of alignment, code
and CRC errors. Overruns have no effect upon this statistic.
14.3.2.20.1.8 Rx Jabbers (Offset = 1Ch)
The total number of jabber frames received on the port. A jabber frame:
•
Was any data or MAC control frame which matched a unicast, broadcast or multicast address, or
matched due to promiscuous mode
•
Was greater than rx_maxlen in bytes
•
Had no CRC error, alignment error or code error
See the Rx Align/Code Errors and Rx CRC errors statistic descriptions for definitions of alignment, code
and CRC errors. Overruns have no effect upon this statistic.
14.3.2.20.1.9 Undersize (Short) Rx Frames (Offset = 20h)
The total number of undersized frames received on the port. An undersized frame is defined to be:
•
Was any data frame which matched a unicast, broadcast or multicast address, or matched due to
promiscuous mode
•
Was greater than rx_maxlen in bytes
•
Had no CRC error, alignment error or code error
See the Rx Align/Code Errors and Rx CRC errors statistic descriptions for definitions of alignment, code
and CRC errors. Overruns have no effect upon this statistic.
14.3.2.20.1.10 Rx Fragments (Offset = 24h)
The total number of frame fragments received on the port. A frame fragment is defined to be:
•
Any data frame (address matching does not matter)
•
Less than 64 bytes long
•
Having a CRC error, an alignment error, or a code error
•
Not the result of a collision caused by half duplex, collision based flow control
See the Rx Align/Code Errors and Rx CRC errors statistic descriptions for definitions of alignment, code
and CRC errors. Overruns have no effect upon this statistic.
14.3.2.20.1.11 Rx Start of Frame Overruns (Offset = 84h)
The total number of frames received on the port that had a CPDMA start of frame (SOF) overrun or were
dropped by due to FIFO resource limitations. SOF overrun frame is defined to be:
1213
SPRUH73H – October 2011 – Revised April 2013
Ethernet Subsystem
Copyright © 2011–2013, Texas Instruments Incorporated