
NXP Semiconductors
PNX15xx/952x Series
Volume 1 of 1
Chapter 23: LAN100 — Ethernet Media Access Controller
PNX15XX_PNX952X_SER_N_4
NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 4.0 — 03 December 2007
23-698
Table 6 lists the components of the receive status structure.
Each Receive Status Structure consists of two words. The StatusTimeStamp word
contains a copy of the Time-stamp Counter value at the time the reception
completed. If the fragment is not the last fragment of the packet, the status reects
the value of the time-stamp when the fragment buffer was lled completely. If the
fragment is the last in a multi-packet reception, the time-stamp will be a copy of the
Time-stamp Counter at the moment the MII Interface generates the status. The
StatusInfo word contains ags returned by the MII Interface and ags generated by
the Receive Datapath reecting the status of the reception.
Table 7 lists the bit
denitions in the StatusInfo word.
Table 6: Receive Status Structure
Name
Address
Offset
Size
Function
StatusInfo
0x0
31:0
Receive status return ags, see table
7StatusTimeStamp
0x4
31:0
time-stamp of the receive completion
Table 7: Receive Status Information Word
Bit
Name
Function
31
Error
An error occurred during reception of this packet. This is a logic OR
of AlignmentError, RangeError, LengthError, SymbolError and
CRCError.
30
LastFrag
When set, this bit indicates this descriptor is the last fragment of a
packet. If the packet consists of a single fragment, this bit is also set.
29
NoDescriptor
No new Rx descriptor is available, and the frame is too long for the
buffer size in the current receive descriptor.
28
Overrun
Receive overrun. The adapter can not accept the data stream or the
status stream.
27
AlignmentErro
r
An alignment error is agged when dribble bits are detected or a
CRC error is detected. This is in accordance with IEEE std.
802.3/clause 4.3.2. (See RSV[26] & RSV[20].)
26
RangeError
The received packet exceeds maximum packet size. (See RSV[22].)
25
LengthError
The frame length eld value in the packet does not match the actual
data byte-length, and species an invalid length. (See RSV[21].)
24
SymbolError
The PHY reports a bit error over the MII Interface during reception.
(See RSV[19].)
23
CRCError
CRC error. (See RSV[20].)
22
Broadcast
The received packet is of type broadcast. (See RSV[25].)
21
Multicast
A multicast packet has been received. (See RSV[24].)
20
FailFilter
Indicates this packet has failed the Rx lter. These packets are not
supposed to pass to memory. But because of the limitation of buffer
FIFO size, part of this packet may already have been passed to
memory. Once the packet was found to have failed the Rx lter, the
remainder of the packet will be discarded without passing to
memory. However, if Command.PassRxFilter is set, the whole
packet will be passed to memory.
19
VLAN
Indicates a VLAN frame. (See RSV[30].)