Techniques employing flits for clock gating

1. A method comprising:

identifying a destination of a transaction;

generating a power flit configured to wake at least one component along a route to the destination;

sending the power flit along the route to the destination before sending a data flit, the power flit waking the at least one component on the route;

indicating in a register that the power flit has been sent to the destination; and

indicating in the register that subsequent power flits may be sent to the destination responsive to one or more of:

receipt of a return flit from the destination; and

countdown timer.

2. The method of claim 1 in which the power flit comprises:

a header indicating the destination and a source of the received data.

3. The method of claim 1 in which sending the power flit comprises:

extracting destination data from the received data;

forming the power flit with the destination data; and

transmitting the power flit along the route.

4. The method of claim 1 performed in a network within a semiconductor chip.

5. The method of claim 4 in which the semiconductor chip is incorporated into a device selected from a group consisting of a music player, a video player, an entertainment unit, a navigation device, a communications device, a personal digital assistant (PDA), a fixed location data unit, and a computer.

6. The method of claim 1 , in which waking the at least one component comprises gating on a portion of the at least one component.

7. The method of claim 1 in which sending the power flit includes sending the power flit on a first virtual channel to the exclusion of a second virtual channel.

8. The method of claim 1 further comprising:

checking the register; and

in response to the indication in the register, not sending at least one subsequent power flit to the destination.

9. The method of claim 1 further including waking the destination by the power flit.

10. A system comprising:

means for receiving data intended for a destination;

means for sending a power flit to the destination via a route, the power flit configured to wake components on the route;

means for sending the data as a data flit to the destination via the route after sending the power flit;

means for indicating in a register that the power flit has been sent to the destination; and

means for indicating in the register that subsequent power flits may be sent to the destination responsive to one or more of:

receipt of a return flit from the destination; and

a countdown timer.

11. The system of claim 10 in which the power flit comprises:

a header indicating the destination and a source of the received data.

12. The system of claim 10 in which the means for sending the power flit comprises:

means for extracting destination data from the received data;

means for forming the power flit using the destination data; and

means for transmitting the power flit along the route.

13. The system of claim 10 comprising a network within a semiconductor chip.

14. A computer program product having a non-transitory computer readable medium recording computer program logic, the computer program product comprising:

code to receive data intended for a destination;

code to send a power flit to the destination via a route, the power flit configured to wake at least one component on the route;

code to send the data as a data flit to the destination via the route after sending the power flit;

code to indicate in a register that the power flit has been sent to the destination; and

code to indicate in the register that subsequent power flits may be sent to the destination responsive to one or more of:

receipt of a return flit from the destination; and

a countdown timer.

15. The computer program product of claim 14 in which the power flit comprises:

a header indicating the destination and a source of the received data.

16. The computer program product of claim 14 in which the code to send the power flit comprises:

code to extract destination data from the received data;

code to form the power flit using the destination data; and

code to transmit the power flit along the route.

17. The computer program product of claim 14 further comprising:

code to check the register; and

code to not send at least one subsequent power flit to the destination in response to the indication in the register.

18. A system comprising:

a Network Interface Unit (NIU) configured:

to receive data intended for a destination;

to send a power flit to the destination via a route, the power flit configured to wake components on the route;

to send the data as a data flit to the destination via the route after sending the power flit;

to indicate in a register that the power flit has been sent to the destination; and

to indicate in the register that subsequent power flits may be sent to the destination responsive to one or more of:

receipt of a return flit from the destination; and

a countdown timer.

19. The system of claim 18 in which the NIU is in communication with a network within a semiconductor chip.

20. The system of claim 19 in which the semiconductor chip is incorporated into a device selected from a group consisting of a music player, a video player, an entertainment unit, a navigation device, a communications device, a personal digital assistant (PDA), a fixed location data unit, and a computer.