Freescale Semiconductor MPC8313E Family Reference Manual page 922

Enhanced Three-Speed Ethernet Controllers
typedef unsigned short uint_16; /* choose 16-bit native type */
typedef unsigned int uint_32; /* choose 32-bit native type */
typedef struct rxbd_struct {
uint_16 flags;
uint_16 length;
uint_32 bufptr;
} rxbd;
Table 15-163 describes the fields of the RxBD.
Offset Bits Name
0–1 0 E Empty, written by the eTSEC (when cleared) and by the user (when set).
0 The data buffer associated with this BD is filled with received data, or data reception is aborted due
1 The data buffer associated with this BD is empty, or reception is currently in progress.
1 RO1 Receive software ownership bit.
This field is reserved for use by software. This read/write bit is not modified by hardware, nor does its
value affect hardware.
2 W Wrap, written by user.
0 The next buffer descriptor is found in the consecutive location.
1 The next buffer descriptor is found at the location defined in RBASE.
3 I Interrupt, written by user.
0 No interrupt is generated after this buffer is serviced.
1 IEVENT[RXB] or IEVENT[RXF] are set after this buffer is serviced. This bit can cause an interrupt
4 L Last in frame, written by the eTSEC.
0 The buffer is not the last in a frame.
1 The buffer is the last in a frame.
5 F First in frame, written by the eTSEC.
0 The buffer is not the first in a frame.
1 The buffer is the first in a frame.
6 — Reserved
7 M Miss, written by the eTSEC. (This bit is valid only if the L-bit is set and eTSEC is in promiscuous
mode.)
This bit is set by the eTSEC for frames that were accepted in promiscuous mode, but were flagged as
a "miss" by the internal address recognition; thus, while in promiscuous mode, the user can use the
M-bit to quickly determine whether the frame was destined to this station.
0 The frame was received because of an address recognition hit.
1 The frame was received because of promiscuous mode.
MPC8313E PowerQUICC II Pro Integrated Processor Family Reference Manual, Rev. 3
15-192
Figure 15-152. Mapping of RxBDs to a C Data Structure
Table 15-163. Receive Buffer Descriptor Field Descriptions
to an error condition. The status and length fields have been updated as required.
if enabled (IMASK[RXBEN] or IMASK[RXFEN]). If the user wants to be interrupted only if RXF
occurs, then the user must disable RXB (IMASK[RXBEN] is cleared) and enable RXF
(IMASK[RXFEN] is set).
Description
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