Network interface card accessible during low power consumption mode

• US 6,513,128 B1
• Filed: 11/30/1999
• Issued: 01/28/2003
• Est. Priority Date: 11/30/1999
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Henderson, Nathan, Ross, Jeffrey, Wang, Chi-Lie, Davis, Eric
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): Cao, Chun
• Application Number:
  US09/451,485
• Time in Patent Office: 1,155 Days
• Field of Search: 713/200, 713/310, 713/322, 713/500, 713/600
• US Class Current: 713/600
• CPC Class Codes: G06F 1/32 Means for saving power

Abstract

The present invention allows NIC resources to be accessed through auxiliary power and an ASIC clock while the PC is powered down and while PCI power and the PCI clock are not available. The present invention also provides an alternate path for accessing the NIC registers, downloading keep-alive and alert-on-LAN packets to the transmit packet buffer (TPB), as well as uploading received packets from the receive packet buffer (RPB). The present invention also allows monitoring PCI activity and seamlessly servicing the PCI configuration cycle (when PCI power and the PCI clock are restored) in conjunction with responding to the access through the alternate path (while PCI power and the PCI clock are not available).

Claims

1. A network interface card, comprising:

an alternate access path for allowing access to resources of the network interface card when the network interface card is in a low power consumption mode;

a clock control for supplying an ASIC clock signal to the network interface card when the network interface card is in a low power consumption mode, the ASIC clock signal providing a clock signal for the alternate access path; and

a PCI activity monitor capable of detecting a PCI configuration cycle from a PCI host addressed to the network interface card when the network interface card is in the low power consumption mode, the PCI activity monitor capable of sending a stop request to the alternate access path, the PCI activity monitor capable of sending a retry signal to the PCI host, the PCI activity monitor capable of instructing the clock control to switch from the ASIC clock signal to a PCI clock signal in response to detecting the PCI configuration cycle, the PCI clock signal providing the clock signal to the network interface card to service the PCI configuration cycle.

2. The network interface card of claim 1, wherein the alternate access path is a serial bus.

3. The network interface card of claim 1, wherein a PCI power and a PCI clock signal are not available in the low power consumption mode.

4. The network interface card of claim 1, wherein the PCI activity monitor is also capable of deasserting the stop request to the alternate access path and instructing the clock control to switch from the PCI clock signal back to the ASIC clock signal after the PCI configuration cycle has been serviced by the network interface card if the network interface card is still in the low power consumption mode.

5. A method for servicing a PCI configuration cycle to a network interface card when the network interface card is in a low power consumption mode, the method comprising:

detecting a PCI configuration cycle from a PCI host addressed to the network interface card when the network interface card is in a low power consumption mode;

sending a stop request to an alternate access path to the network interface card to stop access by the alternate access path to the network interface card;

sending a retry signal to the PCI host so that the PCI host will resend the PCI configuration cycle;

switching a clock signal from an ASIC clock signal to a PCI clock signal so that the PCI configuration cycle may be serviced.

6. The method of claim 5, wherein the alternate access path is a serial bus.

7. The method of claim 5, wherein a PCI power and a PCI clock signal are not available in the low power consumption mode.

8. The method of claim 5, further comprising:

deasserting the stop request to the alternate access path to allow access by the alternate access path to the network interface card;

instructing the clock control to switch from the PCI clock signal back to the ASIC clock signal after the PCI configuration cycle has been serviced by the network interface card if the network interface card is still in the low power consumption mode.