NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 616 -
Revision V1.30
NUC97
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T
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CHNIC
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NUA
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EMAC n MAC Command Register (EMACn_MCMDR)
The EMACn_MCMDR provides the control information for EMAC. Some command settings affect
both frame transmission and reception, such as bit FDUP (EMACn_MCMDR[18]), the full/half
duplex mode selection, or bit OPMOD (EMACn_MCMDR[20]), the 100/10M bps mode selection.
Some command settings control frame transmission and reception separately, likes bit TXON
(EMACn_MCMDR[8]) and RXON (EMACn_MCMDR[0]).
Register
Offset
R/W Description
Reset Value
EMACn_MCMD
R
n=0,1
E0x090 R/W EMAC n MAC Command Register
0x0040_0000
31
30
29
28
27
26
25
24
Reserved
SWR
23
22
21
20
19
18
17
16
REFCLKINV
Reserved
OPMOD
Reserved
FDUP
SQECHKEN
SDPZ
15
14
13
12
11
10
9
8
Reserved
NDEF
TXON
7
6
5
4
3
2
1
0
PTP_SRC
MGP_WAKE
SPCRC
AEP
ACP
ARP
ALP
RXON
Bits
Description
[31:25]
Reserved
Reserved.
[24]
SWR
Software Reset
The SWR implements a reset function to make the EMAC return default state. The SWR
is a self-clear bit. This means after the software reset finished, the SWR will be cleared
automatically. Enable SWR can also reset all control and status registers, exclusive of
the control bits EnRMII (EMACn_MCMDR[22]), LBK (EMACn_MCMDR[21]) and OPMOD
(EMACn_MCMDR[20]).
The EMAC re-initial is necessary after the software reset completed.
0 = Software reset completed.
1 = Software reset Enabled.
[23]
REFCLKINV
REFCLK Inverted Control
This bit controls if RMIIx_REFCLK from external PHY is inverted before using by EMAC.
0 = RMIIx_REFCLK not inverted.
1 = RMIIx_REFCLK inverted.
[22:21]
Reserved
Reserved.
[20]
OPMOD
Operation Mode Selection
The OPMOD defines that if the EMAC is operating on 10M or 100M bps mode. The SWR
would not affect OPMOD value.
0 = EMAC operates in 10Mbps mode.
1 = EMAC operates in 100Mbps mode.