1. Apparatus for processing data, said apparatus comprising:
a register file having a plurality of registers for storing respective register data values;
a cache having a plurality of storage locations for storing respective cache data values corresponding to register data values stored within said register file;
a comparator coupled to said register file and to said cache and responsive to a register data value read from said register file and a corresponding cache data value read from said cache to generate a match signal indicating whether said register data value matches said cache data value; and a value selector responsive to said match signal indicating that said register data value does not match said cache data value to determine which of said register data value and said cache data value is correct and to select for output a correct one of said register data value and said cache data value.
2. Apparatus as claimed in claim 1, wherein said cache stores an index value with each cache data value indicating to which of said register data values said cache data value corresponds.
3. Apparatus as claimed in claim 1, wherein said cache includes fewer storage locations than there are registers within said register file.
4. Apparatus as claimed in claim 1, wherein said value selector includes a redundant data checking circuit coupled to said cache and responsive to said cache data value and an associated redundant data checking code to check for changes within said cache data value, said value selector selecting said cache data value as correct if said redundant data checking circuit indicates no changes have occurred in said cache data value and selecting said register data value as correct if said redundant data checking circuit indicates changes have occurred in said cache data value.
5. Apparatus as claimed in claim 4, wherein said redundant data check circuit is a cyclic redundancy checking circuit and said redundant data checking code is a cyclic redundancy checking code.
6. Apparatus as claimed in claim 1, wherein said value selector includes a redundant data checking circuit coupled to said register file and responsive to said register data value and an associated redundant data checking code to check for changes within said register data value, said value selector selecting said register data value as correct if said redundant data checking circuit indicates no changes have occurred in said register data value and selecting said cache data value as correct if said redundant data checking circuit indicates changes have occurred in said register data value.
7. Apparatus as claimed in claim 1, wherein if said match signal indicates that said register data value does not match said cache data value, then output of a data value is delayed and said value selector is triggered to perform said determination and said selection in a following processing cycle.
8. Apparatus as claimed in claim 1, wherein upon detection of a permanent error in a register, said as: storage location within said cache is locked down to store a cache data value for a register data value of said register with a said permanent error.
9. Apparatus as claimed in claim 1, comprising a read buffer coupled to said register file and said cache to store said register data value read from a register and said cache data value read from a storage location during operation of at least said value selector whilst permitting said register and said storage location to be overwritten.
10. Apparatus as claimed in claim 1, wherein said register file comprises at least one of a plurality of read ports and a plurality of write ports.
11. Apparatus as claimed in claim 10, wherein said register file comprises three read ports and two write ports.
12. Apparatus as claimed in claim 1, wherein said cache, said comparator and said value selector operate to provide at least one of soft error protection and permanent error protection.
13. Apparatus as claimed in claim 1 any, wherein said apparatus comprises a microprocessor responsive to program instructions to perform data processing operations.
14. A method of processing data, said method comprising the steps of:
storing register data values within respective ones of a plurality of registers of a register file;
storing cache data values corresponding to register data values stored within said register file within respective ones of a plurality of storage locations of a cache;
in response to a register data value read from said register file and a corresponding cache data value read from said cache, generating a match signal indicating whether said register data value matches said cache data value; and in response to said match signal indicating that said register data value does not match said cache data value, determining which of said register data value and said cache data value is correct and selecting for output a correct one of said register data value and said cache data value.
15. A method as claimed in claim 14, comprising storing an index value with each cache data value indicating to which of said register data values said cache-data value corresponds.
16. A method as claimed in claim 14, wherein said cache includes fewer storage locations than there are registers within said register file.
17. A method as claimed in claim 14, comprising checking for changes within said cache data value using an associated redundant data checking code, said cache data value being selected as correct if said checking indicates no changes have occurred in said cache data value and said register data value being selected as correct if said checking indicates changes have occurred in said cache data value.
18. A method as claimed in claim 16, wherein said redundant data checking code is a cyclic redundancy checking code.
19. A method as claimed in claim 14, comprising checking for changes within said register data value using an associated redundant data checking code, said register data value being selected as correct if said checking indicates no changes have occurred in said register data value and said cache data value being selected as correct if said checking indicates changes have occurred in said register data value.
20. A method as claimed in claim 14, wherein if said match signal indicates that said register data value does not match said cache data value, then output of a data value is delayed and said value said determination and said selection in a following processing cycle are triggered.
21. A method as claimed in claim 14, wherein upon detection of a permanent error in a register, said as storage location within said cache is locked down to store a cache data value for a register data value of said register with a said permanent error.
22. A method as claimed in claim 14, comprising buffering said register data value read from a register and said cache data value read from a storage location during at least said determination and said selection whilst permitting said register and said storage location to be overwritten.
23. A method as claimed in claim 14, wherein said register file comprises at least one of a plurality of read ports and a plurality of write ports.
24. A method as claimed in claim 23, wherein said register file comprises three read ports and two write ports.
25. A method as claimed in claim 14, wherein method provides at least one of soft error protection and permanent error protection.
26. A method as claimed in claim 14, wherein said method is performed within a microprocessor responsive to program instructions to perform data processing operations.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Optical apparatus, comprising,
an optical source for providing output light for providing input signal light, comprising:
a pump source for pumping a four wave mixing (FWM) process with light pulses (\u201cFWM pump light\u201d);
a FWM element in optical communication with said pump source, said FWM element configured for hosting the FWM process to generate, responsive to the FWM pump light, pulses of FWM signal light and FWM idler light having different wavelengths; and
said FWM element comprising a microstructured optical fiber comprising longitudinally extending features that promote guidance in the core of the microstructured optical fiber; and
a laser or amplifier optical device comprising a gain material for providing optical gain at a gain wavelength via a process of stimulated emission responsive to optical pumping with pump light, said laser or amplifier optical device in optical communication with said optical source and receiving one of the FWM signal light and the FWM idler light as input signal light having the gain wavelength for optically seeding with input signal light the laser or amplifier optical device.
2. The optical apparatus of claim 1 wherein said gain material comprises a rare earth doped (RED) material.
3. The optical apparatus of claim 1 wherein said laser or amplifier optical device comprises an optical fiber, said optical fiber comprising said gain material.
4. The optical apparatus of claim 2 wherein said gain material comprises ytterbium and further comprises an ytterbium absorption spectrum.
5. The optical apparatus of claim 2 wherein said pump source comprises a selected RED material that comprises a rare earth comprised by the RED material.
6. The optical apparatus of claim 2 wherein the RED material comprises one or more of holmium, neodymium, erbium, ytterbium or thulium.
7. The optical apparatus of claim 1 wherein said one of the FWM signal light and FWM idler light is substantially single mode and has an average power of at least 2 Watts.
8. The optical apparatus of claim 1 wherein said laser or amplifier optical device receives pump light from a source other than the FWM signal light and other than the FWM idler light.
9. The optical apparatus of claim 1 wherein said optical apparatus comprises a pulse picker for reducing the repetition rate of the input signal light prior to the delivery thereof to the laser or amplifier optical device.
10. The optical apparatus of claim 1 wherein the laser or amplifier optical device comprises an optical amplifier receiving said one of the FWM signal light and FWM idler light for being optically seeded with input signal light, said optical amplifier comprising an optical fiber comprising the gain material for providing the optical gain.
11. The optical apparatus of claim 10 wherein said optical amplifier produces substantially single mode pulses comprising a temporal pulse width of no greater than 100 ps, a pulse energy of at least 50 microjoules and a wavelength of in the range of 900 nanometers to 2500 nanometers.
12. The optical apparatus of claim 10 wherein said optical amplifier produces substantially single mode pulses comprising a peak power of at least 200 Kilowatts and wherein the length of said optical fiber along which said fiber includes said gain material is no greater than 1 meter.
13. The optical apparatus of claim 10 wherein said optical amplifier receives the other of the FWM signal light and FWM idler light as substantially single mode pump light, said optical apparatus configured such that said optical fiber absorbs the substantially single mode pump light along at least part of its length at the rate of at least 5 dB per meter.
14. The optical apparatus of claim 10 wherein said optical amplifier receives the other of the FWM signal light and FWM idler light as pump light, said optical fiber being substantially core pumped with said pump light.
15. The optical apparatus of claim 10 wherein said optical amplifier receives the other of the FWM signal light and FWM idler light as pump light, and wherein said optical apparatus is configured such that said optical fiber absorbs at least 10 dB of said pump light over a length of no greater than 50 cm.
16. The optical apparatus of claim 1 comprising a second FWM element, said second FWM element configured for hosting a second FWM process generating second FWM signal light and second FWM idler light, said laser or amplifier optical device receiving one of said second FWM signal light and second FWM idler light as pump light for optically pumping the laser or amplifier optical device.
17. The optical apparatus of claim 1 wherein said optical apparatus provides output pulses having a time duration of 1 ns or less.
18. The optical apparatus of claim 1 wherein said optical apparatus provides output pulses having a time duration of 200 ps or less.
19. A method of seeding with input light a laser or amplifier device comprising a gain material for providing optical gain at a gain wavelength via a process of stimulated emission responsive to optical pumping with pump light, comprising:
Generating, using a nonlinear element hosting a four wave mixing (FWM) process, at least one of FWM signal light and FWM idler light, the nonlinear element comprising a microstructured optical fiber comprising longitudinally extending features that promote guidance in the core of the microstructured optical fiber; and
seeding the laser or amplifier optical device with one of the FWM signal light pulses and the FWM idler light pulses as input signal light having the gain wavelength of the gain material.
20. The method of claim 19 wherein the gain material comprises a rare earth doped (RED) material comprising ytterbium for providing the optical gain, said gain material further comprising an ytterbium absorption spectrum.
21. Optical apparatus, comprising,
an optical source configured for providing output light for providing input signal light or pump light, comprising:
a pump source for pumping a four wave mixing (FWM) process with light pulses (\u201cFWM pump light\u201d);
a FWM element in optical communication with said pump source, said FWM element configured for hosting the FWM process to generate, responsive to the FWM pump light, pulses of FWM signal light and FWM idler light having different wavelengths; and
said FWM element comprising a microstructured optical fiber comprising longitudinally extending features that promote guidance in the core of the microstructured optical fiber; and
wherein said optical source is configured such that the output light comprises one of the FWM signal light or the FWM idler light as input signal light having a gain wavelength for seeding with input signal light a laser or amplifier optical device comprising a gain material for providing optical gain, where the gain material has absorption and emission spectra defining gain and pumping wavelengths at which, respectively, the gain material is arranged in the device to provide optical gain via a process of stimulated emission responsive to being pumped.
22. The optical apparatus of claim 21 wherein said gain material comprises a rare earth doped material (RED) for providing the optical gain.
23. The optical apparatus of claim 21 wherein said gain material comprises ytterbium and further comprises an ytterbium absorption spectrum.
24. The optical apparatus of claim 21 wherein said optical source comprises an output optical fiber for delivering the output light, said output optical fiber comprising a multimode core having a cross sectional area selected to substantially match the cross sectional area of the pump cladding of a cladding pumped (double clad) optical fiber.
25. The optical apparatus of claim 21 wherein said optical source comprises an output optical fiber for delivering the output light, said output optical fiber comprising a multimode core having a diameter of at least 50 microns.
26. The optical apparatus of claim 22 wherein said pump source comprises a selected RED material that comprises a rare earth comprised by the RED material.