±15kV ESD Protected MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support and flexPWR® Technology in a Small Footprint
Datasheet
Table 5.45 Register 31 - PHY Special Control/Status (continued)
NAME DESCRIPTION
ADDRESS
MODE DEFAULT
31.4:2
Speed Indication
HCDSPEED value:
RO
XXX
[001]=10Mbps Half-duplex
[101]=10Mbps Full-duplex
[010]=100Base-TX Half-duplex
[110]=100Base-TX Full-duplex
31.1
31.0
Reserved
Write as 0; ignore on Read
RW
RW
0
0
Scramble Disable
0 = enable data scrambling
1 = disable data scrambling,
5.3
Interrupt Management
The Management interface supports an interrupt capability that is not a part of the IEEE 802.3
specification. It generates an active low asynchronous interrupt signal on the nINT output whenever
certain events are detected as setup by the Interrupt Mask Register 30.
The Interrupt system on the SMSC LAN8700/8700I has two modes, a Primary Interrupt mode and an
Alternative Interrupt mode. Both systems will assert the nINT pin low when the corresponding mask
bit is set, the difference is how they de-assert the output interrupt signal nINT.
The Primary interrupt mode is the default interrupt mode after a power-up or hard reset, the Alternative
interrupt mode would need to be setup again after a power-up or hard reset.
5.3.1
Primary Interrupt System
The Primary Interrupt system is the default interrupt mode, (Bit 17.6 = ‘0’). The Primary Interrupt
System is always selected after power-up or hard reset.
To set an interrupt, set the corresponding mask bit in the interrupt Mask register 30 (see Table 5.46).
Then when the event to assert nINT is true, the nINT output will be asserted.
When the corresponding Event to De-Assert nINT is true, then the nINT will be de-asserted.
Table 5.46 Interrupt Management Table
Mask
Interrupt Source Flag
ENERGYON
Interrupt Source
ENERGYON
Event to Assert nINT
Rising 17.1a
Event to De-Assert nINT
30.7
30.6
29.7
29.6
17.1
1.5
Falling 17.1 or
Reading register 29
Auto-Negotiation
complete
Auto-Negotiate
Complete
Rising 1.5
Falling 1.5 or
Reading register 29
SMSC LAN8700/LAN8700i
Revision 2.3 (04-12-11)
DATA4S9HEET
SMSC [ SMSC CORPORATION ]
