LAN9500 Datasheet, PDF (100/213 Pages) SMSC Corporation – USB 2.0 to 10/100 Ethernet Controller Promiscuous mode

LAN950x
This state supports wakeup from GPIO assertion, PHY Link Up, and on reception of a frame passing the filtering con-
straints set by the MAC Control Register (MAC_CR). Due to the limited amount of RX FIFO buffering, it is possible that
there will be frames lost when in this state, as the USB resume time greatly exceeds the buffering capacity of the FIFO.
The Wake-On-LAN bit of the Wakeup Status (WUPS) field of the Power Management Control Register (PMT_CTL) is
used to signal wakeup due to reception of a frame passing the aforementioned filtering constraints. This bit, along with
the GPIO [10:0] (GPIOx_INT) bits of the Interrupt Status Register (INT_STS), may be examined to determined the
event(s) causing the wakeup. If GPIO7 is found to have caused the wakeup, the PHY Link Up Enable (PHY_LINK-
UP_EN) bit of the General Purpose IO Wake Enable and Polarity Register (GPIO_WAKE) may be examined to deter-
mined whether a PHY Link Up event or pin event occurred.
Note 1: Wake-On-LAN events MUST NOT be enabled in the Wakeup Control and Status Register (WUCSR)
while operating in the SUSPEND3 state. If any Wake-On-LAN Event is enabled in WUCSR, all
received frames will be dropped. The setting of the Wake-On-Lan Enable (WOL_EN) bit of the Power
Management Control Register (PMT_CTL) is a “don’t care”.
2: The Wake-On-LAN bit of the Wakeup Status (WUPS) is used to signal both Wake-On-LAN events and
wakeup from SUSPEND3 state due to reception of frames passing the filtering constraints set by the MAC
Control Register (MAC_CR). In order to interpret the Wakeup Status (WUPS) without ambiguity, the soft-
ware driver may examine the Suspend Mode (SUSPEND_MODE) field of the Power Management Control
Register (PMT_CTL) to determine the suspend state it is coming out of.
5.12 Wake Events
The following events can wake up/enable the device, depending on the power state.
• USB Host Resume
• VBUS_DET assertion
• Wake On LAN (Wakeup Frame, Magic Packet, Perfect Destination Address Frame, and Broadcast Frame)
• Reception of a “Good Frame” - (Note 5-4) a frame received when no Wake-On-LAN events are enabled in the
Wakeup Control and Status Register (WUCSR) that meets the filtering requirements configured in the MAC Con-
trol Register (MAC_CR).
• PHY Energy Detect
• PHY Link Up
• GPIO[10:0]
Note 5-4 Not Supported by LAN9500/LAN9500i.
Table 5-66 illustrates the wake events permitted in each of the power states.
TABLE 5-66: POWER STATE/WAKE EVENT MAPPING
Power State
USB Host
Resume
Signaling
VBUS_DET
WOL
Good
Frame
Note 5-5
SUSPEND0
YES
SUSPEND1
YES
SUSPEND2
YES
SUSPEND3
YES
Note 5-5
UNPOWERED
NO
NO
NO
NO
NO
YES
YES
NO
NO
NO
NO
NO
NO
NO
YES
NO
PHY
Energy
Detect
NO
YES
NO
NO
NO
PHY
Link Up
YES
NO
NO
YES
GPIO[10:0]
YES
YES
YES
YES
NO
NO
Note 5-5 Not Supported by LAN9500/LAN9500i.
The occurrence of a GPIO wake event causes the corresponding bit in the Interrupt Status Register (INT_STS) to be
set. Before suspending the device, the Host must ensure that any pending wake events are cleared. Otherwise, the
device will immediately be awakened after being suspended.
5.12.1 DETECTING WAKEUP EVENTS
The wakeup detection logic for LAN9500A/LAN9500Ai is a super set of that of LAN9500/LAN9500i. All of these devices
support the ability to generate remote wake events on detection of a GPIO event, WOL event, or Ethernet link status
change (energy detect) as primitives. An extension of the WOL event class, to provide for Perfect DA Frame Received,
DS00001875A-page 100
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