Freescale Semiconductor MPC8260 PowerQUICC II Family Reference Manual page 1220

Fast Ethernet Controller
Bits Name
8 BC Broadcast address. Valid only for the last buffer in a frame (RxBD[L] = 1). The received frame
address is the broadcast address.
9 MC Multicast address. Valid only for the last buffer in a frame (RxBD[L] = 1). The received frame address
is a multicast address other than a broadcast address.
10 LG Rx frame length violation. A frame length greater than the MFLR (maximum frame length) defined
for this FCC is recognized.
11 NO Rx nonoctet aligned frame. A frame that contained a number of bits not divisible by eight is received
and the CRC check at the preceding byte boundary generated an error.
12 SH Short frame. A frame length less than the MINFLR (minimum frame length) defined for this channel
is recognized. This indication is possible only if the FPSMR[RSH] = 1.
13 CR Rx CRC error. This frame contains a CRC error.
14 OV Overrun. A receiver overrun occurred during frame reception.
15 CL Collision. This frame is closed because a collision occurred during frame reception. Set only if a late
collision occurs or if FPSMR[RSH] is set. The late collision definition is determined by the setting of
FPSMR[LCW].
Data length is the number of octets the CP writes into this BD data buffer. It is written by the CP as the
buffer is closed. When this BD is the last BD in the frame (RxBD[L] = 1), the data length contains the total
number of frame octets (including four bytes for CRC). Note that at least as much memory should be
allocated for each receive buffer as the size specified in MRBLR. MRBLR should be divisible by 32 and
not less than 64.
The receive buffer pointer, which points to the first location of the associated data buffer, can reside in
external memory. This value must be divisible by 16.
When a received frame's data length is an exact multiple of MRBLR, the last BD contains only the status
and total frame length.
At least two BDs must be prepared before beginning reception.
Figure 35-9 shows how RxBDs are used during Ethernet reception.
35-24
Table 35-10. RxBD Field Descriptions (continued)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Description
NOTE
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