UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
685 of 1269
NXP Semiconductors
UM10503
Chapter 26: LPC43xx Ethernet
11
DM
Duplex Mode
When this bit is set, the MAC operates in a Full-Duplex mode where it can transmit
and receive simultaneously.
0
R/W
12
LM
Loopback Mode
When this bit is set, the MAC operates in loopback mode at MII. The MII Receive
clock input is required for the loopback to work properly, as the Transmit clock is not
looped-back internally.
0
R/W
13
DO
Disable Receive Own
When this bit is set, the MAC disables the reception of frames in Half-Duplex mode.
When this bit is reset, the MAC receives all packets that are given by the PHY while
transmitting.
This bit is not applicable if the MAC is operating in Full-Duplex mode.
0
R/W
14
FES
Speed
Indicates the speed in Fast Ethernet (MII) mode:
0 = 10 Mbps
1 = 100 Mbps
0
15
PS
Port select
1 = MII (100 Mbp) - this is the only allowed value.
1
RO
16
DCRS
Disable carrier sense during transmission
When set high, this bit makes the MAC transmitter ignore the MII CRS signal during
frame transmission in Half-Duplex mode. This request results in no errors generated
due to Loss of Carrier or No Carrier during such transmission. When this bit is low, the
MAC transmitter generates such errors due to Carrier Sense and will even abort the
transmissions.
0
R/W
19:17
IFG
Inter-frame gap
These bits control the minimum IFG between frames during transmission.
000 = 96 bit times
001 = 88 bit times
010 = 80 bit times
...
000 = 40 bit times
Note that in Half-Duplex mode, the minimum IFG can be configured for 64 bit times
(IFG = 100) only. Lower values are not considered
000
R//W
20
JE
Jumbo Frame Enable
When this bit is set, MAC allows Jumbo frames of 9,018 bytes (9,022 bytes for VLAN
tagged frames) without reporting a giant frame error in the receive frame status.
0
R/W
21
-
Reserved.
0
RO
Table 532. MAC Configuration register (MAC_CONFIG, address 0x4001 0000) bit description
…continued
Bit
Symbol
Description
Reset
value
Access