LAN9500 Datasheet, PDF (99/213 Pages) SMSC Corporation – USB 2.0 to 10/100 Ethernet Controller Promiscuous mode

LAN950x
Note 5-3
All four SUSPEND states are supported by LAN9500A/LAN9500Ai. SUSPEND3 is not supported by
LAN9500/LAN9500i.
Note: If the device is deconfigured, the SUSPEND_MODE field in the Power Management Control Register
(PMT_CTL) resets to 10b.
5.11.3.1 Reset from Suspend
All suspend states must respond to a USB Reset and pin reset, nRESET. The application of these resets result in the
device’s hardware being re-initialized and placed into the NORMAL Unconfigured state.
5.11.3.2 SUSPEND0
This state is entered from the NORMAL state when the device is suspended and the SUSPEND_MODE field in the
Power Management Control Register (PMT_CTL) is set to 00b.
Refer to Section 5.12.2.1, "Enabling GPIO Wake Events," on page 106, Section 5.12.2.2, "Enabling WOL Wake Events,"
on page 107, and Section 5.12.2.4, "Enabling PHY Link Up Wake Events (LAN9500A/LAN9500Ai ONLY)," on page 108
for detailed instructions on how to program events that cause resumption from the SUSPEND0 state.
In this state, the MAC can optionally be programmed to detect a Wake-On-Lan event or Magic Packet event.
GPIO events can be programmed to cause wakeup in this state. For LAN9500A/LAN9500Ai only, if GPIO7 signals the
event, the PHY Link Up Enable (PHY_LINKUP_EN) bit of the General Purpose IO Wake Enable and Polarity Register
(GPIO_WAKE) may be examined to determined whether a PHY Link Up event or pin event occurred.
The Host may take the device out of the SUSPEND0 state at any time.
5.11.3.3 SUSPEND1
This state is entered from the NORMAL state when the device is suspended and the SUSPEND_MODE field in the
Power Management Control Register (PMT_CTL) is set to 01b.
Refer to Section 5.12.2.1, "Enabling GPIO Wake Events," on page 106, and Section 5.12.2.3, "Enabling Link Status
Change (Energy Detect) Wake Events," on page 107 for detailed instructions on how to program events that cause
resumption from the SUSPEND1 state.
In this state, the Ethernet PHY can be optionally programmed for energy detect. GPIO events can also be programmed
to cause wakeup in this state.
The Host may take the device out of the SUSPEND1 state at any time.
5.11.3.4 SUSPEND2
This state is entered from the NORMAL state when the device is suspended and the SUSPEND_MODE field in the
Power Management Control Register (PMT_CTL) is set to 10b. SUSPEND2 is the default suspend mode.
Refer to Section 5.12.2.1, "Enabling GPIO Wake Events," on page 106 for detailed instructions on how to program
events that cause resumption from the SUSPEND2 state.
This state consumes the least amount of power. In this state, the device may only be awakened by the Host or GPIO
assertion.
The state of the Ethernet PHY is lost when entering SUSPEND2. Therefore, Host must reinitialize the PHY after the
device returns to the NORMAL state.
5.11.3.5 SUSPEND3 (Not Supported by LAN9500/LAN9500i)
This state is entered from the NORMAL state when the device is suspended and the SUSPEND_MODE field in the
Power Management Control Register (PMT_CTL) is set to 11b.
Refer to Section 5.12.2.1, "Enabling GPIO Wake Events," on page 106, Section 5.12.2.4, "Enabling PHY Link Up Wake
Events (LAN9500A/LAN9500Ai ONLY)," on page 108, and Section 5.12.2.5, "Enabling “Good Frame” Wake Events
(LAN9500A/LAN9500Ai ONLY)," on page 108 for detailed instructions on how to program events that cause resumption
from the SUSPEND3 state.
In this suspend state, all clocks in the device are enabled and power consumption is similar to the NORMAL state. How-
ever, it allows for power savings in the Host CPU, which greatly exceeds that of the device. The driver may place the
device in this state after prolonged periods of not receiving any Ethernet traffic.
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