Freescale Semiconductor MPC8313E PowerQUICC II Pro Family Reference Manual page 877

Error
Late collision The controller terminates buffer transmission, sets TxBD[LC], closes the buffer, IEVENT[LC], and
IEVENT[TXE]. The controller resumes transmission after TSTAT[THLT] is cleared (and
DMACTRL[GTS] is cleared).
Memory read error A system bus error occurred during a DMA transaction. The controller sets IEVENT[EBERR], DMA
stops sending data to the FIFO which causes an underrun error, and therefore TxBD[UN] is set, but
IEVENT[XFUN] is not set. The TSTAT[THLT] is set. Transmits are continued once TSTAT[THLT] is
cleared.
Data parity error Data in the transmit FIFO was potentially corrupted. The controller sets IEVENT[DPE], but otherwise
continues transmission until halted explicitly.
Babbling transmit error A frame is transmitted which exceeds the MAC's Maximum Frame Length and
MACCFG2[Huge Frame] is a 0. The controller sets IEVENT[BABT] and continues without interruption.
Reception errors are described in
Error
Overrun error The Ethernet controller maintains an internal FIFO buffer for receiving data. If a receiver FIFO buffer
overrun occurs, the controller sets RxBD[OV], sets RxBD[L], closes the buffer, increments the
discarded frame counter (RDRP), and sets IEVENT[RXF], The receiver then enters hunt mode
(seeking start of a new frame).
Busy error A frame is received and discarded due to a lack of buffers. The controller sets IEVENT[BSY] and
increments the discarded frame counter (RDRP). In addition, the RSTAT[QHLT n ] bit is set. RDRP
increments for each frame that is received while the receiver is halted due to a busy condition. The
halted queue resumes reception once the RSTAT[QHLT n ] bit is cleared.
Filed frame to invalid A frame is received and discarded as a result of the filer directing it to an RxBD ring that is currently
queue error not enabled. The controller sets IEVENT[FIQ] and increments the discarded frame counter (RDRP).
Parser error
If the receive frame parser is enabled, a parse error can be flagged as a result of inconsistencies dis-
covered between fields of the embedded packet headers. For example, the L2 header may indicate
an IPv4 header, but the IP version number fails to match. In the event of a parse error, parsing is ter-
minated at the inconsistent header, and the RxFCB[PERR] field indicates at which layer of the proto-
col stack the error was discovered. Receiver function continues regardless of parse errors, but
IEVENT[PERR] is set. The receive queue filer may operate with reduced or default information in
some cases; therefore, filer rule sets should be constructed so as to be tolerant of misformed frames.
Note: Any values in the length/type field between 1500 and 1536 is treated as a length, however, only
illegal packets exist with this length/type since these are not valid lengths and not valid types. These
are treated by the MAC logic as out of range.
Software must confirm the parser and filer results by checking the type/length field after the packet has
been written to memory to see if it falls in this range.
Non-octet error The Ethernet controller handles a nibble of dribbling bits if the receive frame terminates as non-octet
(dribbling bits) aligned and it checks the CRC of the frame on the last octet boundary. If there is a CRC error, the
frame non-octet aligned (RxBD[NO]) error is reported, IEVENT[RXF] is set, and the alignment error
counter increments. The eTSEC relies on the statistics collector block to increment the receive
alignment error counter (RALN). If there is no CRC error, no error is reported.
MPC8313E PowerQUICC™ II Pro Integrated Processor Family Reference Manual, Rev. 2
Freescale Semiconductor
Table 15-150. Transmission Errors (continued)
Table 15-151.
Table 15-151. Reception Errors
Enhanced Three-Speed Ethernet Controllers
Response
Description
15-159