Immediate cut-off protocol and interface for a packet-based bus connecting processors

A network controller connected to a special purpose processor via a bus, the network controller coupling a computer system to a computer network, and comprising:

• first pins connecting the special purpose processor to the network controller, the first pins being used to transmit data between the special purpose processor and the network controller;
• second pins connecting the special purpose processor to the network controller, the second pins being used to indicate whether the data transmitted to the network controller from the special purpose processor is to be forwarded to a memory of the computer system or to the computer network;
• and
• a marker signal pin connecting the special purpose processor to the network controller, the marker signal pin being used to delineate the beginning and ending of a plurality of bytes of data grouped into a data packet and transmitted from the special purpose processor to the network controller.

A network controller connected to a special purpose processor via a bus, the network controller coupling a computer system to a computer network, and comprising:

• first pins connecting the special purpose processor to the network controller, the first pins being used to transmit data between the special purpose processor and the network controller;
• second pins connecting the special purpose processor to the network controller, the second pins being used to indicate whether the data transmitted to the network controller from the special purpose processor is to be forwarded to a memory of the computer system or to the computer network;
• and
• data valid signal pins connecting the special purpose processor to the network controller, the data valid signal pins being used to indicate to the network controller that data being received by the network controller is invalid.

A network controller connected to a special purpose processor via a bus, the network controller coupling a computer system to a computer network, and comprising:

• first pins connecting the special purpose processor to the network controller, the first Dins being used to transmit data between the special purpose processor and the network controller;
• second pins connecting the special purpose processor to the network controller, the second pins being used to indicate whether the data transmitted to the network controller from the special purpose processor is to be forwarded to a memory of the computer system or to the computer network;
• and
• a chip select signal pin connecting the special purpose processor to the network controller, the chip select signal pin, when deactivated by the network controller, causing the special purpose processor to source a high impedance state to the first pins.

A method for interfacing a special purpose processor to a network controller that links a computer system to a network, the method comprising:

• requesting permission, via a first signal line, that data destined for the network be transferred from the special purpose processor to the network controller;
• requesting permission, via a second signal line, that data destined for the computer system be transferred from the special purpose processor to the network controller;
• transferring data to the network controller, via data signal lines, in response to the request for permission via one of the first and second signal lines;
• and forwarding data received at the network controller to the network when the data transferred to the network controller was requested with the first signal line and forwarding the data to the computer system when the data transferred to the network controller was requested with the second signal line.

A method for interfacing a special purpose processor to a network controller that links a computer system to a network, the method comprising:

• requesting permission, via a first signal line, that data destined for the network be transferred from the special purpose processor to the network controller;
• requesting permission, via a second signal line, that data destined for the computer system be transferred from the special purpose processor to the network controller;
• transferring data to the network controller, via data signal lines, in response to the request for permission via one of the first and second signal lines;
• forwarding data received at the network controller to the network when the data transferred to the network controller was requested with the first signal line and forwarding the data to the computer system when the data transferred to the network controller was requested with the second signal line;
• and
• pausing the transfer of the data from the special purpose processor to the network controller in response to the network controller deasserting a chip select signal line connecting the network controller and the special purpose processor.

A method for interfacing a special purpose Processor to a network controller that links a computer system to a network, the method comprising:

• requesting permission, via a first signal line, that data destined for the network be transferred from the special purpose processor to the network controller;
• requesting permission, via a second signal line, that data destined for the computer system be transferred from the special purpose processor to the network controller;
• transferring data to the network controller, via data signal lines, in response to the request for permission via one of the first and second signal lines:
• forwarding data received at the network controller to the network when the data transferred to the network controller was requested with the first signal line and forwarding the data to the computer system when the data transferred to the network controller was requested with the second signal line;
• and
• pausing the transfer of the data from the special purpose processor to the network controller in response to the network controller deasserting a transfer grant signal line connecting the network controller and the special purpose processor.

A method for interfacing a special purpose processor to a network controller that links a computer system to a network, the method comprising:

• requesting permission, via a first signal line, that data destined for the network be transferred from the special purpose processor to the network controller;
• requesting permission, via a second signal line, that data destined for the computer system be transferred from the special purpose processor to the network controller;
• transferring data to the network controller, via data signal lines, in response to the request for permission via one of the first and second signal lines;
• forwarding data received at the network controller to the network when the data transferred to the network controller was requested with the first signal line and forwarding the data to the computer system when the data transferred to the network controller was requested with the second signal line;
• and
• notifying the network controller that data received on the data signal lines is invalid by deasserting a data valid signal line connecting the special purpose processor and the network controller.

A method for interfacing a special purpose processor to a network controller that links a computer system to a network, the method comprising:

• requesting permission, via a first signal line, that data destined for the network be transferred from the special purpose processor to the network controller;
• requesting permission, via a second signal line, that data destined for the computer system be transferred from the special purpose processor to the network controller;
• transferring data to the network controller, via data signal lines, in response to the request for permission via one of the first and second signal lines;
• forwarding data received at the network controller to the network when the data transferred to the network controller was requested with the first signal line and forwarding the data to the computer system when the data transferred to the network controller was requested with the second signal line, wherein data forwarded to the network is assembled into packets;
• and
• indicating the beginning and ending of a data packet by asserting a marker signal line that connects the network controller to the special purpose processor.

A computer network comprising:

• a first computer system;
• a public network connecting the first computer system to a second computer system;
• the first computer system further comprising:
• a cryptographic processor;
• a network controller coupling the first computer system to the public network;
• first signal lines connecting the cryptographic processor to the network controller, the first signal lines being used to transmit data between the cryptographic processor and the network controller;
• and
• second signal lines connecting the cryptographic processor to the network controller, the second signal lines indicating whether the data transmitted to the network controller from the cryptographic processor is to be transmitted to a memory of the first computer system or to the second computer system over the public network.

A special purpose processor connected to a network controller via a bus, the special purpose processor comprising:

• data signal pins connecting the special purpose processor to the network controller, the data signal pins being used to transmit data between the special purpose processor and the network controller, the transmitted data being organized as packets each containing a plurality of bytes of data;
• a chip select signal pin connecting the special purpose:
• processor to the, network controller, the special purpose processor responding to a deassertion of the chip select signal pin by the network controller by stopping transmission of a packet and presenting a high impedance state to the data signal pins, and, when the chip select signal pin is subsequently asserted by the network controller, the special purpose processor resuming transmission of the packet to the network controller at a point within the packet corresponding to the location where the special purpose processor stopped transmitting the packet;
• and
• signal pins connecting the special purpose processor to the network controller, the signal pins being used to indicate whether the packets transmitted to the network controller from the special purpose processor are to be forwarded to a local computer memory or to an entity connected to the bus via an Ethernet network.

A method for interfacing a special purpose processor to a network controller, the method comprising:

• transferring a plurality of bytes of data from the special purpose processor to the network controller, the plurality of bytes being arranged as packets of data;
• interrupting the data transfer when the network controller deassert a chip select line connecting the special purpose processor to the network controller, the interruption of the data transfer occurring while one of the packets is being transferred, and before the packet has completed the transfer to the network controller;
• resuming transfer of the interrupted packet, when the network controller reasserts the chip select line, at a point within the packet corresponding to the location where the special purpose processor interrupt ted the data transfer;
• requesting permission, via a first signal line, that data destined for an Ethernet network connected to the network controller be transferred from the special purpose processor to the network controller;
• and
• requesting permission, via a second signal line, that data destined for a computer memory local to the network controller be transferred from the special purpose processor to the network controller;
• wherein transferring the plurality of bytes of data from the special purpose processor to the network controller is performed in response to the request for permission via one of the first and second signal lines, and the network controller forwards data received at the network controller to the network when the data transferred to the network controller was requested with the first signal line and forwarding the data to the computer system when the data transferred to the network controller was requested with the second signal line.

A network controller comprising:

• a first set of output pins for transferring data organized as packets to a bus, each packet containing a plurality of bytes of information;
• a chip select pin that, when deasserted by the network controller, indicates that one of the packets being received by the network controller from a processor connected to the bus are to cease being transmitted by the processor, and, when subsequently asserted by the network controller, the chip select pin indicating to the processor that the processor is to resume transmitting the packet to the network controller beginning at a point within the packet corresponding to the location where the processor ceased transmitting the packet;
• and
• pins for indicating whether the transferred packets transmitted are to be forwarded to a local computer memory or to an entity connected to the bus via an Ethernet network.