LAN9420 Datasheet, PDF (81/171 Pages) SMSC Corporation – Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
detailed in Table 3.23 below. The state transitions noted in this table refer to those specified in Section
3.7.4, "Power States," on page 76.
CONDITION
T9
T6
T1, T3
T10, T11
T5 (D3RST)
Table 3.23 PHY Resets
VAUXDET
0
1
X
1
X
PME_EN
X
X
0
0
0
MODE
Normal
General Power-Down
General Power-Down
General Power-Down
Normal
3.7.6
Detecting Power Management Events
LAN9420/LAN9420i supports the ability to generate PCI wake events using nPME on detection of a
Magic Packet, Wakeup Frame or Ethernet link status change (energy detect). A simplified diagram of
the wake event detection logic is shown in Figure 3.29.
MAC Wakeup
Event
WOL_EN
(PMT_CTRL Register)
RW
WUPS[1]
(PMT_CTRL Register)
ED_EN
(PMT_CTRL Register)
RW
PME_EN
(PCI_PMCSR Register)
RW
PME_STATUS
(PCI_PMCSR Register)
WAKE_INT
(Interrupt Controller)
nPME
(PCI Bus)
PHY Interrupt
WUPS[0]
(PMT_CTRL Register)
Figure 3.29 Wake Event Detection Block Diagram
Two control bits are implemented in the PMT_CTRL SCSR: Wake-on-LAN enable (WOL_EN) and
Energy Detect enable (ED_EN). Depending on the state of these control bits, the logic will generate
an internal wake event interrupt when the MAC detects a wakeup event (Wakeup Frame or Magic
Packet), or a PHY interrupt is asserted (energy detect). Two Wakeup Status (WUPS) are implemented
in the SCSR space. These bits are set depending on the corresponding wake event. (See Section
4.2.9, "Power Management Control Register (PMT_CTRL)," on page 98 for further information)
Wakeup Frame detection must be enabled in the MAC before detection can occur. Likewise, the
energy detect interrupt must be enabled in the PHY before this interrupt can be used as a wake event.
If LAN9420/LAN9420i is properly configured, the internal wake event interrupt will cause the assertion
of the nPME signal on detection of a wake event.
When the device is in the D0_A state, wake event detection can also trigger the assertion of a PCI
interrupt (nINT). Upon detection of the wake event, the wake logic sets the Wake Event Interrupt
SMSC LAN9420/LAN9420i
81
DATASHEET
Revision 1.6 (07-18-11)