In-Band Sleep Protocol for Embedded Bus
First Claim
1. A method for controlling sleep mode in a device having a receive port and a transmit port, the method comprising:
- establishing one location of a plurality of locations in a first device accessible via a communication bus as a sleep/wake control location;
receiving a command to store a sleep value in the sleep/wake control location using a transaction on the communication bus to indicate no pending traffic for the receive port;
determining that there is no pending traffic on the transmit port; and
placing the first device in a sleep mode.
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Accused Products
Abstract
A sleep protocol is provided for controlling sleep mode in a device having a receive port and a transmit port. A location is established in a map of locations in the device as a sleep/wake control location. When the device receives a command to store a sleep value in the sleep/wake control location, this indicates there is no pending traffic for the receive port. When the device also determines that there is no pending traffic on the transmit port, then the device may enter a low power sleep mode. When the device receives a command to store a wake value in the sleep/wake control location to indicate pending traffic for the receive port, it awakens from sleep mode and responds to the wake command with a reply command to indicate the receive port is ready to receive the pending traffic.
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Citations
20 Claims
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1. A method for controlling sleep mode in a device having a receive port and a transmit port, the method comprising:
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establishing one location of a plurality of locations in a first device accessible via a communication bus as a sleep/wake control location; receiving a command to store a sleep value in the sleep/wake control location using a transaction on the communication bus to indicate no pending traffic for the receive port; determining that there is no pending traffic on the transmit port; and placing the first device in a sleep mode. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for controlling sleep mode in a plurality of devices coupled via a communication bus, each device having a receive port and a transmit port, the method comprising:
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establishing one location of a plurality of locations in each of the plurality of devices accessible via a communication bus as a sleep/wake control location; establishing a logical address assignment for each of the plurality of device; establishing a transport channel between a pair of the devices using the logical addresses of the pair of devices, such that a transmit port of each of the pair of devices is logically coupled to a receive port of the corresponding device via the communication bus; determining that there is no pending traffic on the transmit port of a first device of the pair of devices and therefore no pending traffic on the receive port of the second device of the pair of devices; sending a command via the communication bus from the first device to the second device to store a sleep value in the sleep/wake control location of the second device to indicate no pending traffic for the receive port of the second device; determining that there is no pending traffic on the transmit port of the second device and therefore no pending traffic on the receive port of the first device; sending a command via the communication bus from the second device to the first device to store a sleep value in the sleep/wake control location of the second device to indicate no pending traffic for the receive port of the first device; allowing the first device to enter a sleep mode while there is no pending traffic on the receive port of the first device and no pending traffic on the transmit port of the first device; and allowing the second device to enter a sleep mode while there is no pending traffic on the receive port of the second device and no pending traffic on the transmit port of the second device. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A system, comprising:
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a plurality of devices communicatively coupled via a communication bus, wherein each of the devices comprises; a receive port configured to receive data via the communications bus; a transmit port configured to transmit data via the communications bus; queue logic coupled to the transmit port, the queue logic operable to hold data pending transmission; transmit logic configured to determine when data is pending for the transmit port; receive logic configured to determine when data is pending for the receive port; functional logic coupled to receive data from the receive port, the functional logic configured to be placed in a low power sleep mode; and sleep control logic coupled to the functional logic, operable to allow the functional logic to enter the sleep mode while the receive logic indicates no pending data for the receive port and the transmit logic indicates no pending data for the transmit port. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification