Motorola PowerQUICC II MPC8280 Series Reference Manual page 1333

Table 36-10. RxBD Field Descriptions (continued)
Bits Name
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.
MOTOROLA
Freescale Semiconductor, Inc.
NOTE
Chapter 36. Fast Ethernet Controller
For More Information On This Product,
Go to: www.freescale.com
Description
Ethernet RxBDs
36-27