UM10503
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User manual
Rev. 1.3 — 6 July 2012
757 of 1269
NXP Semiconductors
UM10503
Chapter 26: LPC43xx Ethernet
Table 590. Receive descriptor fields 0 (RDES0)
Bit
Symbol
Description
0
ESA
Extended Status Available/Rx MAC Address
When Advanced Timestamp is present, this bit, when set, indicates that the
extended status is available in descriptor word 4 (RDES4). This is valid only
when the Last Descriptor bit (RDES0[8]) is set. When Advance Timestamp
Feature is not selected, this bit indicates Rx MAC Address status. When set,
this bit indicates that the Rx MAC Address registers value (1 to 31) matched
the frame’s DA field. When reset, this bit indicates that the Rx MAC Address
Register 0 value matched the DA field.
1
CE
CRC Error
When set, this bit indicates that a Cyclic Redundancy Check (CRC) Error
occurred on the received frame. This field is valid only when the Last
Descriptor (RDES0[8]) is set.
2
DE
Dribble Bit Error
When set, this bit indicates that the received frame has a non-integer multiple
of bytes (odd nibbles). This bit is valid only in MII Mode.
3
RE
Receive Error
When set, this bit indicates that the receive error signal is asserted while
receive data valid signal is asserted during frame reception. This error also
includes carrier extension error in MII and Half-duplex mode. Error can be of
less/no extension, or error (rxd
0f) during extension.
4
RWT
Receive Watchdog Timeout
When set, this bit indicates that the Receive Watchdog Timer has expired
while receiving the current frame and the current frame is truncated after the
Watchdog Timeout.
5
FT
Frame Type
When set, this bit indicates that the Receive Frame is an Ethernet-type frame
(the LT field is greater than or equal to 0x0600). When this bit is reset, it
indicates that the received frame is an IEEE802.3 frame. This bit is not valid
for Runt frames less than 14 bytes.
6
LC
Late Collision
When set, this bit indicates that a late collision has occurred while receiving
the frame in Half-Duplex mode.
7
TSA
Timestamp Available when Advanced Timestamp feature is present.
When set, this bit indicates that a snapshot of the Timestamp is written in
descriptor words 6 (RDES6) and 7 (RDES7). This is valid only when the Last
Descriptor bit (RDES0[8]) is set.
8
LS
Last Descriptor
When set, this bit indicates that the buffers pointed to by this descriptor are the
last buffers of the frame
9
FS
First Descriptor
When set, this bit indicates that this descriptor contains the first buffer of the
frame. If the size of the first buffer is 0, the second buffer contains the
beginning of the frame. If the size of the second buffer is also 0, the next
Descriptor contains the beginning of the frame.
10
VLAN
VLAN Tag
When set, this bit indicates that the frame pointed to by this descriptor is a
VLAN frame tagged by the MAC Core.
11
OE
Overflow Error
When set, this bit indicates that the received frame was damaged due to
buffer overflow in MTL.