FDC37B727-NS Standard Microsystems (SMSC), FDC37B727-NS Datasheet - Page 84

• Manufacturer Part Number: FDC37B727-NS
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37B727-NS

• Pin Count: 128
• Lead Free Status / RoHS Status: Compliant

enabled, a frequency detection filter is placed in
the path to the soft power management block,
SMI and PME interface that generates an active
low pulse for the duration of a signal that
produces 3 edges in a 200msec time period i.e.,
detects a pulse train of frequency 15Hz or higher.
This filter circuit runs off of the 32 kHz clock. This
circuit is powered by the VTR power supply.
When this circuit is disabled, it will draw no
current.
The nRING function is part of the soft power
management block as an additional wakeup
event, and the SMI and PME interface logic.
1.
•
•
2.
A status and enable bit is in the soft power
status and enable registers as follows:
RING Status bit - R/W: RING_STS, Bit 3 of
Soft Power Status Register 2 (Logical
Device 8, 0xB3); latched, cleared on read.
1= Ring indicator input occurred on the
nRING pin and, if enabled, caused the
wakeup (activated nPowerOn). 0= nRING
input did not occur.
RING Enable bit - R/W: RING_EN, Bit 3 of
Soft Power Enable Register 2 (Logical
Device 8, 0xB1). 1=Enable ring indication
on nRING pin as wakeup function to activate
nPowerOn. 0=Disable.
An enable bit is in the SMI Enable Register
1 as follows:
84
3.
•
•
Refer to Logical Device 8, 0xC6 for programming
information
The ring wakeup filter will produce an active low
pulse for the period of time that nRING, nRI1
and/or nRI2 is toggling.
RING Enable bit - R/W: RING_EN, Bit 0 of
SMI Register 1 (System I/O Space, at
<PM1_BLK>+14h). 1=Enable ring indication
on nRING pin as SMI function. 0=Disable.
Note: The PME status bit for RING is used
as the SMI status bit for RING (see PME
Status Register).
A status and enable bit is in the PME status
and enable registers as follows:
RING Status bit - R/W: RING_STS, Bit 5 of
PME Status Register 1 (System I/O Space,
at <PM1_BLK>+Ch); latched, cleared by
writing a “1” to this bit. 1= Ring indicator
input occurred on the nRING pin and, if
enabled, caused the nPME/SCI or SMI. 0=
nRING input did not occur.
RING Enable bit - R/W: RING_EN, Bit 5 of
PME Enable Register 1 (System I/O Space,
at
indication on nRING pin as PME wakeup
function. 0=Disable.
<PM1_BLK>+Eh).
See figure below.
1=Enable
ring