Datasheet
Micrel, Inc. KS8721BL/SL
June 2009
20
M9999-062509-1.3
Address Name Description Default
(1)
Mode
1.13 100BASE-TX Half-Duplex
1 = capable of 100BASE-X half-duplex
0 = not capable of 100BASE-X half-duplex
RO 1
1.12 10BASE-T Full-Duplex
1 = 10Mbps with full-duplex
0 = no 10Mbps with full-duplex capability
RO 1
1.11 10BASE-T Half-Duplex
1 = 10Mbps with half-duplex
0 = no 10Mbps with half-duplex capability
RO 1
1.10:7 Reserved RO 0
1.6 No Preamble
1 = preamble suppression
0 = normal preamble
RO 1
1.5 Auto-Negotiation Complete
1 = auto-negotiation process completed
0 = auto-negotiation process not completed
RO 0
1.4 Remote Fault
1 = remote fault
0 = no remote fault
RO/LH 0
1.3 Auto-Negotiation Ability
1 = capable to perform auto-negotiation
0 = unable to perform auto-negotiation
RO 1
1.2 Link Status
1 = link is up
0 = link is down
RO/LL 0
1.1 Jabber Detect
1 = jabber detected
0 = jabber not detected. Default is low
RO/LH 0
1.0 Extended Capability 1 = supports extended capabilities registers RO 1
Register 2h - PHY Identifier 1
2.15:0 PHY ID Number
Assigned to the 3rd through 18th bits of the organizationally
unique identifier (OUI). Micrel’s OUI is 0010A1 (hex).
RO 0022h
Register 3h - PHY Identifier 2
3.15:0 PHY ID Number
Assigned to the 19th through 24th bits of the
organizationally unique identifier (OUI). Micrel’s OUI is
0010A1 (hex).
RO 000101
3.9:4 Model Number Six bit manufacturer’s model number RO 100001
3.3:0 Revision Number Four bit manufacturer’s model number RO 1001
Register 4h - Auto-Negotiation Advertisement
4.15 Next Page
1 = next page capable
0 = no next page capability
RW 0
4.14 Reserved RO 0
4.13 Remote Fault
1 = remote fault supported
0 = no remote fault
RW 0
4.12:11 Reserved RO 0
4.10 Pause
1 = pause function supported
0 = no pause function
RW 0
4.9 100BASE-T4
1 = T4 capable
0 = no T4 capability
RO 0
4.8 100BASE-TX Full-Duplex
1 = TX with full-duplex
0 = no TX full-duplex capability
RW
Set by
SPD100 &
DUPLEX
4.7 100BASE-TX
1 = TX capable
0 = no TX capability
RW
Set by
SPD100
4.6 10BASE-T Full-Duplex
1 = 10Mbps with full-duplex
0 = no 10Mbps full-duplex capability
RW
Set by
DUPLEX