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 by a slave PHY coupled to the master PHY via a communication link, the method comprising:
transmitting a wake-up command from the slave PHY to the master PHY;
monitoring, for a first period after transmitting the wake-up command, the communication link at the slave PHY for a transmission from the master PHY comprising a signal to begin link training; and
retransmitting, after the first period, the wake-up command from the slave PHY to the master PHY in response to not receiving the transmission from the master PHY during the first period.
2 . The method of claim 1 further comprising:
monitoring, for a second period after retransmitting the wake-up command, the communication link at the slave PHY for the transmission from the master PHY; and
again retransmitting, after the second period, the wake-up command from the slave PHY to the master PHY in response to not receiving the transmission from the master PHY during the second period.
3 . The method of claim 2 wherein the second period is equal to the first period.
4 . The method of claim 1 further comprising retransmitting the wake-up command from the slave PHY to the master PHY a predetermined number of times.
5 . The method of claim 4 further comprising ceasing transmission of the wake-up command from the slave PHY to the master PHY after the slave PHY not receiving the transmission from the master PHY in response to the slave PHY retransmitting the wake-up command to the master PHY the predetermined number of times.
6 . A slave PHY coupled to a master PHY via a communication link and configured to wake up the master PHY from a low-power mode, the slave PHY comprising:
an input/output (I/O) circuitry configured to transmit a wake-up command to the master PHY via the communication link; and
a processing circuitry configured to:
monitor, for a first period after transmitting the wake-up command using the I/O circuitry, the communication link for a transmission from the master PHY, the transmission including a signal to begin link training; and
retransmit, after the first period, the wake-up command to the master PHY using the I/O circuitry in response to not receiving the transmission from the master PHY during the first period.
7 . The slave PHY of claim 6 wherein the processing circuitry is configured to:
monitor, for a second period after retransmitting the wake-up command using the I/O circuitry, the communication link for the transmission from the master PHY; and
again retransmit, after the second period, the wake-up command to the master PHY using the I/O circuitry in response to not receiving the transmission from the master PHY during the second period.
8 . The slave PHY of claim 7 wherein the second period is equal to the first period.
9 . The slave PHY of claim 6 wherein the processing circuitry is configured to retransmit the wake-up command to the master PHY using the I/O circuitry a predetermined number of times.
10 . The slave PHY of claim 9 wherein the processing circuitry is configured to cease transmission of the wake-up command to the master PHY using the I/O circuitry after not receiving the transmission from the master PHY in response to retransmitting the wake-up command the predetermined number of times.
11 . A system comprising:
a master PHY; and
a slave PHY coupled to the master PHY via a communication link, the slave PHY configured to:
transmit a wake-up command to the master PHY;
monitor, for a first period after transmitting the wake-up command, the communication link for a transmission from the master PHY comprising a signal to begin link training; and
retransmit, after the first period, the wake-up command to the master PHY in response to not receiving the transmission from the master PHY during the first period.
12 . The system of claim 11 wherein the slave PHY is configured to:
monitor, for a second period after retransmitting the wake-up command, the communication link for the transmission from the master PHY; and
again retransmit, after the second period, the wake-up command to the master PHY in response to not receiving the transmission from the master PHY during the second period.
13 . The system of claim 12 wherein the second period is equal to the first period.
14 . The system of claim 11 wherein the slave PHY is configured to retransmit the wake-up command to the master PHY a predetermined number of times.
15 . The system of claim 14 wherein the slave PHY is configured to cease transmission of the wake-up command to the master PHY after not receiving the transmission from the master PHY in response to retransmitting the wake-up command the predetermined number of times.
16 . A slave PHY coupled to a master PHY via a communication link and configured to wake up the master PHY from a low-power mode, the slave PHY comprising:
transmitting means for transmitting a wake-up command to the master PHY via the communication link; and
monitoring means for monitoring, for a first period after the transmitting means transmits the wake-up command, the communication link for a transmission from the master PHY, the transmission including a signal to begin link training,
wherein the transmitting means retransmits, after the first period, the wake-up command to the master PHY in response to the monitoring means not receiving the transmission from the master PHY during the first period.
17 . The slave PHY of claim 16 wherein:
the monitoring means monitors, for a second period after the transmitting means retransmits the wake-up command, the communication link for the transmission from the master PHY; and
the transmitting means again retransmits, after the second period, the wake-up command to the master PHY in response to the monitoring means not receiving the transmission from the master PHY during the second period.
18 . The slave PHY of claim 17 wherein the second period is equal to the first period.
19 . The slave PHY of claim 16 wherein the transmitting means retransmits the wake-up command to the master PHY a predetermined number of times.
20 . The slave PHY of claim 19 wherein the monitoring means ceases transmission of the wake-up command to the master PHY by the transmitting means after the monitoring means not receiving the transmission from the master PHY in response to the transmitting means retransmitting the wake-up command the predetermined number of times.