lan8187 Standard Microsystems Corp., lan8187 Datasheet - Page 50

• Manufacturer Part Number: lan8187
• Description: Lan8187/lan8187i ?15kv Esd Protected Mii/rmii 10/100 Ethernet Transceiver With Hp Auto-mdix & Flexpwr Technology
• Manufacturer: Standard Microsystems Corp.

a.
Revision 1.5 (01-10-08)
5.3.2
5.3.2.1
Mask
30.7
30.6
30.5
30.4
30.3
30.2
30.1
If the mask bit is enabled and nINT has been de-asserted while ENERGYON is still high, nINT will assert for
256 ms, approximately one second after ENERGYON goes low when the Cable is unplugged. To prevent an
unexpected assertion of nINT, the ENERGYON interrupt mask should always be cleared as part of the
ENERGYON interrupt service routine.
29.7
29.6
29.5
29.4
29.3
29.2
29.1
Note: The ENERGYON bit 17.1 is defaulted to a ‘1’ at the start of the signal acquisition process,
Alternate Interrupt System
The Alternative method is enabled by writing a ‘1’ to 17.6 (ALTINT).
To set an interrupt, set the corresponding bit of the in the Mask Register 30, (see
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.
Note: The ENERGYON bit 17.1 is defaulted to a ‘1’ at the start of the signal acquisition process,
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.
2. Clear the Mask bit 30.1
Interrupt Source Flag
Remote Fault Detected
Parallel Detection Fault
Auto-Negotiation Page
Auto-Negotiation LP
Auto-Negotiation
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.
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.
Achnowledge
ENERGYON
Or
Link Down
complete
Received
Table 5.47 Alternative Interrupt System Management Table.
17.1
5.14
1.5
1.4
1.2
6.4
6.1
±15kV ESD Protected MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX & flexPWR
Interrupt Source
DATASHEET
Parallel Detection
Page Received
Auto-Negotiate
Remote Fault
Acknowledge
ENERGYON
Link Status
Complete
Fault
50
Event to Assert
Rising 17.1
Rising 5.14
Falling 1.2
Rising 1.4
Rising 6.1
Rising 1.5
Rising 6.4
nINT
Condition to
De-Assert.
17.1 low
5.14 low
1.2 high
1.5 low
1.4 low
6.4 low
6.1 low
SMSC LAN8187/LAN8187i
Table
5.47).
Bit to Clear
TM
Datasheet
nINT
29.7
29.6
29.5
29.4
29.3
29.2
29.1
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