SMSC LAN9312 - Manual (Page 46)

High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
Revision 1.4 (08-19-08) 46 SMSC LAN9312
DATASHEET
4.3 Power Management
The LAN9312 Port 1 and Port 2 PHYs and the Host MAC support several power management and
wakeup features.
The LAN9312 can be programmed to issue an external wake signal (PME) via several methods,
including wake on LAN, wake on link status change (energy detect), and magic packet wakeup. The
PME signal is ideal for triggering system power-up using remote Ethernet wakeup events. A simplified
diagram of the logic that controls the PME and PME_INT signals can be seen in
Figure 4.1 .
The PME module handles the latching of the Port 1 & 2 PHY Energy-Detect Status (ED_STS1 and
ED_STS2) and Wake-On LAN Status (WOL_STS) bits of the
Power Management Control Register
(PMT_CTRL) . This module also masks the status bits with the corresponding enable bits (ED_EN1,
ED_EN2, WOL_EN) and combines the results together to generate the PME_INT status bit in the
Interrupt Status Register (INT_STS) . The PME_INT status bit is then masked with the PME_EN bit and
conditioned before becoming the PME output pin.
The PME output characteristics can be configured via the PME_TYPE, PME_IND, and PME_POL bits
of the
Power Management Control Register (PMT_CTRL) . These bits allow the PME to be open-drain,
active high push-pull, or active-low push-pull and configure the output to be continuous, or pulse for
50mS.
Table 4.3 Hard-Strap Configuration Strap Definitions
STRAP NAME DESCRIPTION PIN
eeprom_type_strap EEPROM Type Strap: Configures the EEPROM type.
0 = Microwire Mode
1 = I
2
C Mode
EEPROM_TYPE
eeprom_size_strap[1:0] EEPROM Size Strap [1:0]: Configures the EEPROM size
range as specified in
Section 10.2, "I2C/Microwire Master
EEPROM Controller," on page 137 .
EEPROM_SIZE_[1:0]
phy_addr_sel_strap PHY Address Select Strap: Configures the default MII
management address values for the PHYs and Virtual PHY
as detailed in
Section 7.1.1, "PHY Addressing," on page 82 .
PHY_ADDR_SEL
P
H
Y
_
ADDR_SEL_
S
TRA
P
VALUE
V
IRT
UAL PHY
ADDRESS
PO
R
T
1
P
H
Y
ADDRESS
PO
R
T
2
P
H
Y
ADDRESS
0 0 1 2
1 1 2 3