Register-based de-skew system and method for a source synchronous receiver

1. A de-skew system for a source synchronous receiver, comprising:

a de-skew strobe generator for generating a plurality of de-skew strobe signals based on at least an incoming strobe signal, wherein only one of said deskew strobe signals will be active at a time;

a plurality of de-skew registers for receiving input data originated from a transmitting domain at a particular clock frequency, each of said deskew registers operating responsive to a corresponding one of said plurality of de-skew strobe signals for spreading out a respective input data pulse over an expanded timing window into a spread data pulse;

a bank of multiplexer (MUX) elements coupled to said de-skew registers for multiplexing data from each of said spread data pulses; and

a bank of data capture registers coupled to said bank of MUX elements for capturing said multiplexed data in response to a clock signal associated with said source synchronous receiver.

2. The de-skew system for a source synchronous receiver as set forth in claim 1 , wherein said plurality of de-skew registers comprises four de-skew registers, each of which registers operating responsive to one of four de-skew strobe signals generated by said de-skew strobe generator.

3. The de-skew system for a source synchronous receiver as set forth in claim 2 , wherein said bank of MUX elements comprises two 2:1 MUX elements, a first 2:1 MUX element operating to multiplex spread data pulse outputs of first and third de-skew registers and a second 2:1 MUX operating to multiplex spread data pulse outputs of second and fourth de-skew registers.

4. The de-skew system for a source synchronous receiver as set forth in claim 3 , wherein a first data capture register is operable to capture multiplexed data from said first 2:1 MUX element.

5. The de-skew system for a source synchronous receiver as set forth in claim 4 , wherein a second data capture register is operable to capture multiplexed data from said second 2:1 MUX element.

6. The de-skew system for a source synchronous receiver as set forth in claim 5 , wherein each of said 2:1 MUX elements is controlled by a control signal manufactured from second and fourth de-skew strobe signals.

7. The de-skew system for a source synchronous receiver as set forth in claim 5 , wherein said four de-skew strobe signals are manufactured by said de-skew strobe generator responsive to a pair of incoming strobe signals.

8. The de-skew system for a source synchronous receiver as set forth in claim 7 , wherein said de-skew strobe generator includes:

a first flip-flop whose clock input is coupled to a first one of said pair of incoming strobe signals;

a second flip-flop whose clock input is coupled to a second one of said pair of incoming strobe signals; and

a combinational logic block coupled to outputs of said first and second flipflops for generating said four de-skew strobe signals.

9. The de-skew system for a source synchronous receiver as set forth in claim 8 , wherein said combinational logic block includes four 2-input AND gates.

10. The de-skew system for a source synchronous receiver as set forth in claim 7 , wherein said input data is clocked such that each input data pulse is about 2 nanoseconds.

11. The de-skew system for a source synchronous receiver as set forth in claim 10 , wherein said spread data pulse associated with each input data pulse is about 8 nanoseconds.

12. A de-skewing method for use with a source synchronous receiver circuit domain, comprising:

generating a plurality of one-hot de-skew strobe signals based on at least an incoming strobe signal from a transmitter circuit domain;

registering, responsive to said one-hot de-skew strobe signals, each input data pulse from said transmitter circuit domain into a respective register so as to stretch each input data pulse into a spread data pulse over an extended timing window;

multiplexing data from said spread data pulses; and

registering multiplexed data using a clock signal associated with said source synchronous receiver circuit domain.

13. The de-skewing method for use with a source synchronous receiver circuit domain as set forth in claim 12 , further comprising the operation of forwarding said multiplexed data upon registration to core circuitry associated with said source synchronous receiver circuit domain.

14. The de-skewing method for use with a source synchronous receiver circuit domain as set forth in claim 12 , wherein two single-ended incoming strobe signals are provided for manufacturing four de-skew strobe signals.

15. The de-skewing method for use with a source synchronous receiver circuit domain as set forth in claim 14 , wherein said each input data pulse is about 2 nanoseconds.

16. The de-skewing method for use with a source synchronous receiver circuit domain as set forth in claim 15 , wherein said spread data pulse is stretched over a timing window of about 8 nanoseconds.

17. The de-skewing method for use with a source synchronous receiver circuit domain as set forth in claim 14 , wherein said spread data pulses are multiplexed using two 2:1 MUX elements.

18. The de-skewing method for use with a source synchronous receiver circuit domain as set forth in claim 14 , wherein each of said 2:1 MUX elements is controlled by a control signal manufactured from two of said four de-skew strobe signals.

19. A de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain, comprising:

means for generating a plurality of one-hot de-skew strobe signals based on at least an incoming strobe signal from said transmitter circuit domain;

means for registering, responsive to said one-hot de-skew strobe signals, each input data pulse from said transmitter circuit domain into a respective register so as to stretch each input data pulse into a spread data pulse over an extended timing window;

means for multiplexing data from said spread data pulses; and

means for registering multiplexed data using a receiver circuit clock signal associated with said receiver circuit domain.

20. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 19 , wherein said receiver, circuit clock signal is synchronous with a transmitter circuit clock, signal associated with said transmitter circuit domain.

21. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 19 , wherein said means for registering said input data pulses comprises four de-skew registers, each operating responsive to a corresponding one of said one-hot de-skew strobe signals.

22. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 21 , wherein said means for multiplexing comprises two 2:1 MUX elements, a first 2:1 MUX element operating to multiplex spread data pulse outputs of first and third de-skew registers and a second 2:1 MUX element operating to multiplex spread data pulse outputs of second and fourth de-skew registers.

23. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 22 , wherein said means for registering said multiplexed data comprises a first data capture register operable to capture multiplexed data from said first 2:1 MUX element and a second data capture register operable to capture multiplexed data from said second 2:1 MUX element.

24. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 23 , wherein each of said 2:1 MUX elements is controlled by a control signal manufactured from second and fourth de-skew strobe signals.

25. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 19 , wherein said one-hot de-skew strobe signals are manufactured responsive to a pair of incoming strobe signals provided by said transmitter circuit domain.

26. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 25 , wherein said means for generating said de-skew strobe signals comprises:

a first flip-flop whose clock input is coupled to a first one of said pair of incoming strobe signals;

a second flip-flop whose clock input is coupled to a second one of said pair of incoming strobe signals; and

a combinational logic block coupled to outputs of said first and second flip-flops for generating said four de-skew strobe signals.

27. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 26 , wherein said combinational logic block includes four 2-input AND gates, each for outputting a one-hot de-skew strobe signal.

28. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 27 , wherein said input data pulses are clocked such that each input data pulse is about 2 nanoseconds.

29. The de-skewing circuit operable with respect to transferring data from a transmitter circuit domain to a receiver circuit domain as set forth in claim 28 , wherein said spread data pulse associated with each input data pulse is about 8 nanoseconds.