Bidirectional ring-based interconnection networks for multiprocessors

A multiprocessor chip comprising:

• a plurality of nodes;
• a plurality of ring stations, which are each associated with one of the plurality of node, that are interconnected via a clockwise ring network and a counterclockwise ring network, wherein a first ring station associated with a first node of the plurality of nodes is configured to:
• receive a command for execution;
• based at least in part on a determination that the clockwise ring network and the counterclockwise ring network are both available for transmission, perform a bidirectional execution of the command by:
• transmit a first warning signal on the clockwise ring network indicating that the command will be transmitted on the clockwise ring network a first number of clock cycles after the first warning signal;
• transmit a second warning signal on the counterclockwise ring network indicating that the command will be transmitted on the counterclockwise ring network a second number of clock cycles after the second warning signal, wherein the first warning signal and the second warning signal are transmitted during a same clock cycle;
• transmit, during the first number of clock cycles after the first warning signal, the command on the clockwise ring network;
• and
• transmit, during the second number of clock cycles after the second warning signal, the command on the counterclockwise ring network, wherein the second number differs from the first number by exactly one clock cycle,
• wherein the plurality of nodes consists of an even number of nodes and a diagonal node of the first node is a node that is an equal number of hops from the first node via the clockwise ring network and the counterclockwise ring network, and
• wherein a diagonal ring station is configured to:
• receive a first set of partial responses to the command via the clockwise ring network;
• receive a second set of partial responses to the command via the counterclockwise ring network;
• create a set of combined responses based on the first set of partial responses and the second set of combined responses;
• transmitting, during a first cycle, the set of combined responses on the clockwise ring network;
• and
• transmitting, during a second cycle subsequent to the first cycle, the set of combined responses on the counterclockwise ring network.

A system comprising:

• a memory having computer readable instructions;
• and
• a multiprocessor chip for executing the computer readable instructions, the multiprocessor chip comprising:
• a plurality of nodes;
• a plurality of ring stations, which are each associated with one of the plurality of node, that are interconnected via a clockwise ring network and a counterclockwise ring network, wherein a first ring station associated with a first node of the plurality of nodes is configured to:
• receive a command for execution;
• based at least in part on a determination that the clockwise ring network and the counterclockwise ring network are both available for transmission, perform a bidirectional execution of the command by:
• transmit a first warning signal on the clockwise ring network indicating that the command will be transmitted on the clockwise ring network a first number of clock cycles after the first warning signal;
• transmit a second warning signal on the counterclockwise ring network indicating that the command will be transmitted on the counterclockwise ring network a second number of clock cycles after the second warning signal, wherein the first warning signal and the second warning signal are transmitted during a same clock cycle;
• transmit, during the first number of clock cycles after the first warning signal, the command on the clockwise ring network;
• and
• transmit, during the second number of clock cycles after the second warning signal, the command on the counterclockwise ring network, wherein the second number differs from the first number by exactly one clock cycle,
• wherein the plurality of nodes consists of an even number of nodes and a diagonal node of the first node is a node that is an equal number of hops from the first node via the clockwise ring network and the counterclockwise ring network, and
• wherein a diagonal ring station is configured to:
• receive a first set of partial responses to the command via the clockwise ring network;
• receive a second set of partial responses to the command via the counterclockwise ring network;
• create a set of combined responses based on the first set of partial responses and the second set of combined responses;
• transmitting, during a first cycle, the set of combined responses on the clockwise ring network;
• and
• transmitting, during a second cycle subsequent to the first cycle, the set of combined responses on the counterclockwise ring network.