Datasheet

±15kV ESD Protected MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support and flexPWR
®
Technology in a Small Footprint
Datasheet
SMSC LAN8700/LAN8700i 49 Revision 2.3 (04-12-11)
DATASHEET
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.
31.4:2 Speed Indication HCDSPEED value:
[001]=10Mbps Half-duplex
[101]=10Mbps Full-duplex
[010]=100Base-TX Half-duplex
[110]=100Base-TX Full-duplex
RO XXX
31.1 Reserved Write as 0; ignore on Read RW 0
31.0 Scramble Disable 0 = enable data scrambling
1 = disable data scrambling,
RW 0
Table 5.46 Interrupt Management Table
Mask Interrupt Source Flag Interrupt Source Event to Assert nINT Event to De-Assert nINT
30.7 29.7 ENERGYON 17.1 ENERGYON Rising 17.1
a
Falling 17.1 or
Reading register 29
30.6 29.6 Auto-Negotiation
complete
1.5 Auto-Negotiate
Complete
Rising 1.5 Falling 1.5 or
Reading register 29
Table 5.45 Register 31 - PHY Special Control/Status (continued)
ADDRESS NAME DESCRIPTION MODE DEFAULT