Claims
- 1. A method for measuring access time comprising:
determining the frequency of a ring oscillator containing a device under test; determining the frequency of a similar ring oscillator which doesn't contain said device under test; and calculating access time of said device under test by comparing said frequencies.
- 2. The method of claim 1, wherein said comparing is performed at the output of a frequency divider circuit coupled to said ring oscillator.
- 3. A method for measuring access time comprising:
determining the frequency of a ring oscillator containing a device under test, said ring oscillator including a frequency divider circuit; determining the frequency of a similar ring oscillator which doesn't contain said device under test, said ring oscillator containing a frequency divider circuit; and calculating access time of said device under test by comparing said frequencies at the outputs of said frequency divider circuits.
- 4. An integrated circuit comprising:
an on-chip measurement circuit, said on-chip measurement circuit containing a ring oscillator that facilitates frequency measurements both with circuitry under test in said ring oscillator and also free-running with said circuitry under test out of said ring oscillator.
- 5. The integrated circuit of claim 4 wherein the access time of said circuitry under test is the difference between said frequencies.
- 6. The integrated circuit of claim 4 wherein said ring oscillator contains a pulse generator.
- 7. The integrated circuit of claim 6, wherein said pulse generator creates a clock pulse for said circuitry under test every time the output changes.
- 8. The integrated circuit of claim 4, wherein said frequency measurements are performed at the output of a frequency divider circuit coupled to said ring oscillator.
- 9. The integrated circuit of claim 8 wherein the access time of said circuitry under test is the difference between said frequency measurements.
- 10. A memory comprising:
an on-chip measurement circuit, said on-chip measurement circuit containing a ring oscillator that facilitates frequency measurements both with circuitry under test in said ring oscillator and also free-running with said circuitry under test out of said ring oscillator.
- 11. The integrated circuit of claim 10 wherein the access time of said circuitry under test is the difference between said frequencies.
- 12. The integrated circuit of claim 10 wherein said ring oscillator contains a pulse generator.
- 13. The integrated circuit of claim 12, wherein said pulse generator creates a clock pulse for said circuitry under test every time the output changes.
- 14. The integrated circuit of claim 10, wherein said frequency measurements are performed at the output of a frequency divider circuit coupled to said ring oscillator.
- 15. The integrated circuit of claim 14 wherein the access time of said circuitry under test is the difference between said frequency measurements.
- 16. An integrated circuit comprising:
an on-chip measurement circuit, said on-chip measurement circuit containing a ring oscillator that facilitates frequency measurements both with memory circuitry in said ring oscillator and also free-running with said memory circuitry out of said ring oscillator.
- 17. The integrated circuit of claim 16 wherein the access time of said memory circuitry is the difference between said frequencies.
- 18. The integrated circuit of claim 16 wherein said ring oscillator contains a pulse generator.
- 19. The integrated circuit of claim 18, wherein said pulse generator creates a clock pulse for said memory circuitry every time the output changes.
- 20. The integrated circuit of claim 16, wherein said frequency measurements are performed at the output of a frequency divider circuit coupled to said ring oscillator.
- 21. The integrated circuit of claim 20 wherein the access time of said memory circuitry is the difference between said frequency measurements.
Parent Case Info
[0001] CROSS-REFERENCE To RELATED APPLICATIONS This application is related to application Ser. No. ______ (Attorney Docket Number TI-34810) filed on the same date as this application and entitled “Oscillation Based Cycle Time Measurement”. With its mention in this section, this patent application is not admitted to be prior art with respect to the present invention.