Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface

Datasheet

detection. Refer to section Section 3.7.6, "Detecting Power Management Events," on page 80 for more information.

3.7.4.3.2EXITING THE D0A STATE

The device will exit the D0A state under the following conditions. State transitions are illustrated in Figure 3.28 on page 75.

„D0A to D3HOT (T3): This transition occurs when, during normal device operation, the Host system selects the “D3” state in the Power Management State (PM_STATE) field of the PCI Power Management Control and Status Register (PCI_PMCSR). (PCInRST=1, PM_STATE=00b to 11b, VAUXDET=X, PWRGOOD=1). If the PME Enable (PME_EN) bit in the PCI Power Management Control and Status Register (PCI_PMCSR) is cleared, the internal PHY is reset and is placed in the General Power-Down mode on this transition. If PME Enable (PME_EN) is set, it is assumed that the device will be required to detect Ethernet power management events and the PHY is not reset or placed in General Power-Down mode.

„D0A to D0U (T7): This transition occurs when PCInRST is asserted while in the D0A state (PCInRST=1 to 0, PM_STATE=00b, VAUXDET=X, PWRGOOD=1).

„D0A to D3COLD (T11): This transition occurs when all power supplies are operational and the device has been initialized and the Power Management State (PM_STATE) field of the PCI Power Management Control and Status Register (PCI_PMCSR) is set to “D0”, and then PCI power is turned off and 3.3Vaux is still operational (PCInRST=1, PM_STATE=00b, VAUXDET=1, PWRGOOD=1 to 0).The internal PHY is reset and is placed in the General Power-Down mode on this transition. Note that if VAUXDET=0, the device is being powered from the PCI +3.3V supply and will turn off (G3) when PCI power is removed.

„D0A to G3 (T12): This transition occurs when all power supplies are turned off (PCInRST=X, PM_STATE=XXb, VAUXDET=1 to 0, PWRGOOD=1 to 0). For example, total power failure.

3.7.4.4The D3HOT State

In this state the PCI power is on, but normal Ethernet receive and transmit operation is disabled. In

D3HOT power is reduced by disabling the internal PLL and derivative clocks. If the PME Enable (PME_EN) bit in the PCI Power Management Control and Status Register (PCI_PMCSR) is cleared, power is also conserved by placing the internal PHY into General Power-Down mode on transition to this state.

In D3HOT PCI configuration accesses are permitted, but the device will not respond to PCI memory or I/O accesses. While in this state, the Power Management State (PM_STATE) field of the PCI Power Management Control and Status Register (PCI_PMCSR) will indicate a setting of 11b (D3 state).

3.7.4.4.1POWER MANAGEMENT EVENTS IN D3HOT

If configured to do so, the device is capable of detecting MAC (WOL, Magic Packet) and PHY (link status change) wake events and is capable of asserting nPME as a result of detection. Refer to section Section 3.7.6, "Detecting Power Management Events," on page 80 for more information.

3.7.4.4.2EXITING THE D3HOT STATE

The device will exit the D3HOT state under the following conditions. State transitions are illustrated in Figure 3.28 on page 75.

„D3HOT to D3COLD (T4): This transition occurs after the device has been placed in the D3HOT state by the Host system and then PCI power is turned off, but PCI 3.3Vaux remains operational (PCInRST=X, PM_STATE=11b, VAUXDET=1, PWRGOOD=1 to 0). In this state the device is powered by the PCI 3.3Vaux supply.

„D3HOT to D0U (T5): This transition occurs when the device is in the D3HOT state and Host system selects the “D0” state in the Power Management State (PM_STATE) field of the PCI Power Management Control and Status Register (PCI_PMCSR) (PCInRST=1, PM_STATE=11b to 00b, VAUXDET=X, PWRGOOD=1). A D3 Transition Reset (D3RST) occurs during this transition. Refer to Section 3.7.5, "Resets," on page 79 to for more information on this reset.

SMSC LAN9420/LAN9420i

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Revision 1.22 (09-25-08)

 

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