Method and apparatus for performing timed functions in a wireless electronic device
Methods and apparatus for performing timed functions in battery-powered, wireless electronic devices, such as sensors or control modules. Such electronic devices comprise a main processor and a co-processor. When the main processor enters a quiescent state in order to preserve battery life, one or more timed functions are transferred from the main processor to the co-processor just before the main processor enters the quiescent state. When the co-processor determines that it is time to perform the timed function, the co-processor wakes the main processor in order for the main processor to perform the timed function.
1. A battery-powered, electronic device, comprising:
a memory for storing processor-executable instructions;
a co-processor; and
a main processor coupled to the co-processor and the memory for executing the processor-executable instructions that causes the main processor to:
determine that the main processor will enter a quiescent state;
identify a timed function that is being maintained by the main processor, the timed function comprising a function performed by the main processor that is dependent on time;
send an identification of the timed function and a parameter associated with the timed function to the co-processor; and
enter the quiescent state after sending the identification and the parameter to the co-processor.
2. The battery-powered, electronic device of claim 1 , wherein the processor-executable instructions comprise further instructions that causes the main processor to:
receive a wake signal from the co-processor after entering the quiescent state;
after receiving the wake signal, receive the identification of the timed function and an updated parameter from the co-processor associated with the timed function; and
execute the timed function in accordance with the updated parameter.
3. The battery-powered, electronic device of claim 1 , wherein the instructions that causes the main processor to send the identification and the parameter to the co-processor comprises instructions that causes the main processor to:
periodically send the identification and the parameter to the co-processor, the parameter updated each time the identification and the parameter is sent.
4. The battery-powered, electronic device of claim 2 , wherein the updated parameter comprises a time remaining to perform the timed function.
5. The battery-powered, electronic device of claim 2 , wherein the updated parameter comprises a remaining number of times to perform an action associated with the timed function.
6. The battery-powered, electronic device of claim 2 , wherein the timed function comprises periodic transmission of a heartbeat signal, the battery-powered, electronic device further comprising:
a transmitter coupled to the main processor;
wherein the instructions that causes the main processor to execute the timed function comprises instructions that causes the main processor to:
transmit the heartbeat signal in accordance with the updated parameter from the co-processor.
7. The battery-powered, electronic device of claim 2 , wherein the timed function comprises periodic blinking of an indicator, the battery-powered, electronic device further comprising:
the indicator coupled to the main processor;
wherein the instructions that causes the main processor to execute the timed function comprises instructions that causes the main processor to:
blink the indicator in accordance with the updated parameter from the co-processor.
8. The battery-powered, electronic device of claim 2 , wherein the timed function comprises retransmission of a status message, the battery-powered, electronic device further comprising:
a transmitter coupled to the main processor;
wherein the instructions that causes the main processor to execute the timed function comprises instructions that causes the main processor to:
retransmit the status message in accordance with the updated parameter from the co-processor.
9. The battery-powered, electronic device of claim 1 , wherein the processor-instructions that causes the main processor to determine that the battery-powered, electronic device will enter the quiescent state comprises instructions that causes the main processor to:
determine a remaining time to perform a subsequent action associated with the timed function;
determine that the remaining time exceeds a desirable time to operate the battery-powered, electronic device in a normal operational state; and
enter the quiescent state when the remaining time exceeds the desirable time.
10. A method for performing timed functions by a battery-powered, electronic device, comprising:
determining that the battery-powered, electronic device will enter a quiescent state;
identifying a timed function that is being maintained a main processor of the battery-powered, electronic device, the timed function comprising a function performed by the main processor that is dependent on time;
sending an identification of the timed function and a parameter associated with the timed function to a co-processor coupled to the main processor; and
entering the quiescent state after sending the identification and the parameter from the main processor to the co-processor.
11. The method of claim 10 , further comprising:
receiving a wake signal from the co-processor after entering the quiescent state;
after receiving the wake signal, receiving the identification of the timed function and an updated parameter from the co-processor associated with the timed function; and
executing the timed function by the main processor in accordance with the updated parameter.
12. The method of claim 10 , wherein sending the identification and the parameter to the co-processor comprises:
periodically sending the identification and the parameter to the co-processor, the parameter updated each time the identification and the parameter is sent.
13. The method of claim 11 , wherein the updated parameter comprises a time remaining to perform the timed function.
14. The method of claim 11 , wherein the updated parameter comprises a remaining number of times to perform an action associated with the timed function.
15. The method of claim 11 , wherein the timed function comprises periodic transmission of a heartbeat signal, the method further comprising:
transmitting the heartbeat signal in accordance with the updated parameter.
16. The method of claim 11 , wherein the timed function comprises periodic blinking of an indicator, the method further comprising:
blinking the indicator in accordance with the updated parameter.
17. The method of claim 11 , wherein the timed function comprises retransmission of a status message, the method further comprising:
retransmitting the status message in accordance with the updated parameter.
18. The method of claim 10 , wherein determining that the battery-powered, electronic device will enter the quiescent state comprises:
determining a remaining time to perform a subsequent action associated with the timed function;
determining that the remaining time exceeds a desirable time to operate the battery-powered, electronic device in a normal operational state; and
entering the quiescent state when the remaining time exceeds the desirable time.