Automatic resending of WUP by slave device
Systems and methods are described for a slave PHY device retransmitting a waking up command to a master PHY device in a low-power mode. After transmitting a wake-up command to the master PHY device, the slave PHY device starts a timer. If the timer reaches a threshold time, the slave device retransmits the wake-up command.
1. A method for waking up a master PHY from a low-power mode, the master PHY being disposed in a network including at least the master PHY and a slave PHY, the master and slave PHYs being coupled via a communication link, the method comprising:
transmitting a wake-up command to the master PHY from the slave PHY;
in response to transmitting the wake-up command to the master PHY from the slave PHY, starting a first timer;
monitoring the communication link at the slave PHY for a transmission, from the master PHY, that includes a signal to begin link training;
determining, based on monitoring the communication link, that the first timer has a value that is greater than a first threshold time;
determining, based on the first timer having a value that is greater than the first threshold time, that no transmission that includes a signal to begin link training was received by the slave PHY;
in response to determining that no transmission that includes a signal to begin link training was received by the slave PHY, retransmitting the wake-up command to the master PHY from the slave PHY.
2. The method of claim 1 further comprising:
determining that the first timer has run, without the slave PHY receiving a transmission, from the master PHY, that includes a signal to begin link training for a duration greater than the first threshold time; and
based on determining that no transmission that includes a signal to begin link training was received by the slave PHY, comparing the value of the first timer with the first threshold time.
3. The method of claim 1 further comprising:
in response to transmitting the wake-up command to the master PHY from the slave PHY, incrementing a counter at the slave;
determining that the counter has a value that is greater than a counter threshold.
4. The method of claim 3 further comprising:
in response to determining that the counter has a value that is greater than a counter threshold, preventing further transmissions of wake-up commands.
5. The method of claim 1 , further comprising:
in response to retransmitting the wake-up command to the master PHY from the slave PHY, starting a second timer;
determining that the second timer has a value that is greater than a second threshold time;
in response to determining that the second timer has a value that is greater than a second threshold time, again retransmitting the wake-up command to the master PHY from the slave PHY.
6. The method of claim 5 further comprising determining that the second timer has a value that is greater than the second threshold time that is equal to the first threshold time.
7. The method of claim 5 further comprising determining that the second timer has a value that is greater than the second threshold time different the first threshold time.
8. A slave PHY in a network configured to wake up a master PHY from a low-power mode, the slave PHY comprising:
input/output (I/O) circuitry configured to:
transmit a wake-up command to the master PHY in the network coupled to the slave PHY via a communication link; and
processing circuitry configured to:
in response to the I/O circuitry transmitting a wake-up command to the master PHY in the network coupled to the slave PHY via the communication link, start a first timer;
monitor the communication link for a transmission, from the master PHY, that includes a signal to begin link training;
determine, based on monitoring the communication link, that the first timer has a value that is greater than a first threshold time;
determine, based on the first timer having a value that is greater than the first threshold time, that no transmission that includes a signal to begin link training was received by the slave PHY; and
in response to determining that no transmission that includes a signal to begin link training was received by the slave PHY, retransmit the wake-up command to the master PHY using the I/O circuitry.
9. The slave PHY of claim 8 , wherein the processing circuitry is further configured to:
determine that the first timer has run, without receiving a transmission, from the master PHY, that includes a signal to begin link training for a duration greater than the first threshold time;
based on determining that no transmission that includes a signal to begin link training was received, comparing the value of the first timer with the first threshold time.
10. The slave PHY of claim 8 , wherein the processing circuitry is incapable of establishing the communication link.
11. The slave PHY of claim 8 , wherein the processing circuitry is further configured to:
in response to transmitting the wake-up command to the master PHY, increment a counter;
determine that the counter has a value that is greater than a counter threshold.
12. The slave PHY of claim 11 , wherein the processing circuitry is further configured to:
in response to determining that the counter has a value that is greater than a counter threshold, prevent further transmissions of wake-up commands.
13. The slave PHY of claim 8 , the processing circuitry further configured to:
in response to retransmitting the wake-up command to the master PHY using the I/O circuitry, start a second timer;
determine that the second timer has a value that is greater than a second threshold time; and
in response to determining that the second timer has a value that is greater than a second threshold time, again retransmit the wake-up command to the master PHY using the I/O circuitry.
14. The slave PHY of claim 13 , wherein the processing circuitry is configured to determine that the second timer has a value that is greater than a second threshold time equal to the first threshold time.
15. The slave PHY of claim 13 , wherein the processing circuitry is configured to determine that the second timer has a value that is greater than a second threshold time different from the first threshold time.
16. A system for waking up a master PHY from a low-power mode, the system comprising:
a master PHY;
a slave PHY configured to:
transmit, to the master PHY via a communication link, a wake-up command;
in response to transmitting the wake-up command, start a timer;
monitor the communication link for a transmission, from the master PHY, that includes a signal to begin link training;
determine, based on monitoring the communication link, that the timer has a value that is greater than a threshold time;
determine, based on the first timer having a value that is greater than the first threshold time, that no transmission that includes a signal to begin link training was received; and
in response to determining that no transmission that includes a signal to begin link training was received, retransmit, to the master PHY, the wake-up command.
17. The system of claim 16 , wherein the slave PHY is incapable of establishing the communication link between the master and slave PHY.
18. The system of claim 16 , wherein the slave PHY is further configured to:
based on determining that no transmission that includes a signal to begin link training was received, compare the value of the first timer with the first threshold time.
19. The system of claim 16 , wherein the slave PHY is further configured to:
in response to transmitting, to the master PHY via a communication link, a wake-up command, increment a counter;
determine that the counter has a value that is greater than a counter threshold.
20. The system of claim 16 , wherein the slave PHY is further configured to:
in response to determining that the counter has a value that is greater than a counter threshold, prevent further transmissions of wake-up commands.