Table 5.21 register 0 - basic control, Table 5.22 register 1 - basic status, Datasheet – SMSC FlexPWR LAN8720 User Manual
Page 41
Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
SMSC LAN8720/LAN8720i
41
Revision 1.0 (05-28-09)
DATASHEET
Table 5.21 Register 0 - Basic Control
ADDRESS
NAME
DESCRIPTION
MODE
DEFAULT
0.15
Reset
1 = software reset. Bit is self-clearing. For best results,
when setting this bit do not set other bits in this
register. The configuration (as described in
) is set from the register bit values,
and not from the mode pins.
RW/
SC
0
0.14
Loopback
1 = loopback mode,
0 = normal operation
RW
0
0.13
Speed Select
1 = 100Mbps,
0 = 10Mbps.
Ignored if Auto Negotiation is enabled (0.12 = 1).
RW
Set by
MODE[2:0]
bus
0.12
Auto-
Negotiation
Enable
1 = enable auto-negotiate process
(overrides 0.13 and 0.8)
0 = disable auto-negotiate process
RW
Set by
MODE[2:0]
bus
0.11
Power Down
1 = General power down mode,
0 = normal operation
RW
0
0.10
Isolate
1 = electrical isolation of transceiver from MII
0 = normal operation
RW
0
0.9
Restart Auto-
Negotiate
1 = restart auto-negotiate process
0 = normal operation. Bit is self-clearing.
RW/
SC
0
0.8
Duplex Mode
1 = Full duplex,
0 = Half duplex.
Ignored if Auto Negotiation is enabled (0.12 = 1).
RW
Set by
MODE[2:0]
bus
0.7
Collision Test
1 = enable COL test,
0 = disable COL test
RW
0
0.6:0
Reserved
RO
0
Table 5.22 Register 1 - Basic Status
ADDRESS
NAME
DESCRIPTION
MODE
DEFAULT
1.15
100Base-T4
1 = T4 able,
0 = no T4 ability
RO
0
1.14
100Base-TX Full
Duplex
1 = TX with full duplex,
0 = no TX full duplex ability
RO
1
1.13
100Base-TX Half
Duplex
1 = TX with half duplex,
0 = no TX half duplex ability
RO
1
1.12
10Base-T Full
Duplex
1 = 10Mbps with full duplex
0 = no 10Mbps with full duplex ability
RO
1
1.11
10Base-T Half
Duplex
1 = 10Mbps with half duplex
0 = no 10Mbps with half duplex ability
RO
1
1.10:6
Reserved
1.5
Auto-Negotiate
Complete
1 = auto-negotiate process completed
0 = auto-negotiate process not completed
RO
0