LAN8187_06 Datasheet, PDF (50/72 Pages) SMSC Corporation – ±15kV ESD Protected MII/RMII Fast-Ethernet PHY with HP Auto-MDIX and SMSC flexPWRTM

±15kV ESD Protected MII/RMII Fast-Ethernet PHY with HP Auto-MDIX and SMSC flexPWR^TM
Datasheet
To set an interrupt, set the corresponding bit of the in the Mask Register 30, (see Table 5.46).
To Clear an interrupt, either clear the corresponding bit in the Mask Register (30), this will de-assert
the nINT output, or Clear the Interrupt Source, and write a ‘1’ to the corresponding Interrupt Source
Flag. Writing a ‘1’ to the Interrupt Source Flag will cause the state machine to check the Interrupt
Source to determine if the Interrupt Source Flag should clear or stay as a ‘1’. If the Condition to De-
Assert is true, then the Interrupt Source Flag is cleared, and the nINT is also de-asserted. If the
Condition to De-Assert is false, then the Interrupt Source Flag remains set, and the nINT remains
asserted.
Table 5.46 Alternative Interrupt System Management Table.
Mask
Interrupt Source Flag
Interrupt Source
30.7 29.7
ENERGYON
17.1
30.6 29.6
Auto-Negotiation
1.5
complete
30.5 29.5 Remote Fault Detected 1.4
30.4 29.4
Link Down
1.2
30.3 29.3 Auto-Negotiation LP 5.14
Achnowledge
30.2 29.2 Parallel Detection Fault 6.4
30.1 29.1 Auto-Negotiation Page 6.1
Received
ENERGYON
Auto-Negotiate
Complete
Remote Fault
Link Status
Acknowledge
Parallel Detection
Fault
Page Received
Event to Assert
nINT
Rising 17.1
Rising 1.5
Condition to
De-Assert.
17.1 low
1.5 low
Bit to Clear
nINT
29.7
29.6
Rising 1.4
1.4 low
29.5
Falling 1.2
1.2 high
29.4
Rising 5.14
5.14 low
29.3
Rising 6.4
6.4 low
29.2
Rising 6.1
6.1 low
29.1
5.3.2.1
Note: The ENERGYON bit 17.1 is defaulted to a ‘1’ at the start of the signal acquisition process,
therefore the Interrupt source flag 29.7 will also read as a ‘1’ at power-up. If no signal is
present, then both 17.1 and 29.7 wil clear within a few milliseconds.
Example Alternative Interrupts system
For example 30.7 is set to ‘1’ to enable the ENERGYON interrupt. After a cable is plugged in,
ENERGYON (17.1) goes active and nINT will be asserted low.
To de-assert the nINT interrupt output, either.
1. Clear the ENERGYON bit (17.1), by removing the cable, then writing a ‘1’ to register 29.7.
Or
2. Clear the Mask bit 30.1
5.4
Miscellaneous Functions
5.4.1
Carrier Sense
The carrier sense is output on CRS. CRS is a signal defined by the MII specification in the IEEE 802.3u
standard. The PHY asserts CRS based only on receive activity whenever the PHY is either in repeater
mode or full-duplex mode. Otherwise the PHY asserts CRS based on either transmit or receive activity.
The carrier sense logic uses the encoded, unscrambled data to determine carrier activity status. It
activates carrier sense with the detection of 2 non-contiguous zeros within any 10 bit span. Carrier
sense terminates if a span of 10 consecutive ones is detected before a /J/K/ Start-of Stream Delimiter
pair. If an SSD pair is detected, carrier sense is asserted until either /T/R/ End–of-Stream Delimiter
pair or a pair of IDLE symbols is detected. Carrier is negated after the /T/ symbol or the first IDLE. If
/T/ is not followed by /R/, then carrier is maintained. Carrier is treated similarly for IDLE followed by
some non-IDLE symbol.
Revision 1.0 (12-14-06)
50
DATASHEET
SMSC LAN8187/LAN8187I