Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
Revision 1.0 (05-28-09) 44 SMSC LAN8720/LAN8720i
DATASHEET
Table 5.27 Register 6 - Auto Negotiation Expansion
ADDRESS NAME DESCRIPTION MODE DEFAULT
6.15:5 Reserved RO 0
6.4 Parallel Detection
Fault
1 = fault detected by parallel detection logic
0 = no fault detected by parallel detection logic
RO/
LH
0
6.3 Link Partner Next
Page Able
1 = link partner has next page ability
0 = link partner does not have next page ability
RO 0
6.2 Next Page Able 1 = local device has next page ability
0 = local device does not have next page ability
RO 0
6.1 Page Received 1 = new page received
0 = new page not yet received
RO/
LH
0
6.0 Link Partner Auto-
Negotiation Able
1 = link partner has auto-negotiation ability
0 = link partner does not have auto-negotiation ability
RO 0
Table 5.28 Register 16 - Silicon Revision
ADDRESS NAME DESCRIPTION MODE DEFAULT
16.15:10 Reserved RO 0
16.9:6 Silicon Revision Four-bit silicon revision identifier. RO 0001
16.5:0 Reserved RO 0
Table 5.29 Register 17 - Mode Control/Status
ADDRESS NAME DESCRIPTION MODE DEFAULT
17.15:14 Reserved Write as 0; ignore on read. RW 0
17.13 EDPWRDOWN Enable the Energy Detect Power-Down mode:
0 = Energy Detect Power-Down is disabled
1 = Energy Detect Power-Down is enabled
RW 0
17.12 Reserved Write as 0, ignore on read RW 0
17.11 LOWSQEN The Low_Squelch signal is equal to LOWSQEN AND
EDPWRDOWN.
Low_Squelch = 1 implies a lower threshold
(more sensitive).
Low_Squelch = 0 implies a higher threshold
(less sensitive).
RW 0
17.10 MDPREBP Management Data Preamble Bypass:
0 – detect SMI packets with Preamble
1 – detect SMI packets without preamble
RW 0
17.9 FARLOOPBACK Force the module to the FAR Loop Back mode, i.e. all
the received packets are sent back simultaneously (in
100Base-TX only). This bit is only active in RMII
mode, as described in Section 5.3.8.2. This mode
works even if MII Isolate (0.10) is set.
RW 0
17.8:7 Reserved Write as 0, ignore on read. RW 00