Method and system for programming a memory device

• US 6,661,724 B1
• Filed: 06/13/2002
• Issued: 12/09/2003
• Est. Priority Date: 06/13/2002
• Status: Active Grant

• Current Assignee: Longitude Flash Memory Solutions, Ltd. (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Snyder, Warren, Rouse, Mark
• Primary Examiner(s): NGUYEN, TAN
• Application Number:
  US10/172,670
• Time in Patent Office: 544 Days
• Field of Search: 365/211, 365/185.18, 365/185.28, 365/185.09
• US Class Current: 365/211
• CPC Class Codes: G11C 16/10 Programming or data input circuits
• CPC Class Codes: G11C 7/04 with means for avoiding disturbances due to temperature effects
• CPC Class Codes: G11C 7/1045 Read-write mode select circuits

Abstract

A method for programming a memory device is disclosed. In one method embodiment, the present invention receives a measurement from a temperature sensor located near a non-volatile programmable memory device. Next, a transformation is accessed. Then, the measurement from the temperature sensor is processed in conjunction with the transformation to establish a programming time for a memory device as a function of a programming voltage and the temperature of the memory device. The programming voltage is then applied to the memory device for the length of time specified by the programming time during the programming pulse of the memory device to accurately program the device using an optimum amount of current.

Claims

1. A method for programming a memory device comprising:

accessing a measurement from a temperature sensor near said memory device;

indexing a transformation with said measurement from said temperature sensor to access a programming time for said memory device based on a programming voltage and said temperature; and

applying said programming voltage to said memory device for a length of time specified by said programming time to program data into said memory device.

2. The method as recited in claim 1 wherein said temperature sensor, said transformation, and said memory device are disposed within an integrated circuit.

3. The method as recited in claim 2 wherein said indexing is performed by a processor coupled to said integrated circuit.

4. The method as recited in claim 3 wherein said processor is a microprocessor on a microcontroller programmable system on a chip (PSOC).

5. The method as recited in claim 2 wherein said applying said programming voltage is performed by a voltage pump coupled to said integrated circuit.

6. The method as recited in claim 2, wherein said programming time for applying said programming voltage is measured by a pulse width generator coupled to said integrated circuit.

7. The method as recited in claim 1 wherein said transformation is a memory table.

8. The method as recited in claim 1 wherein said transformation is an equation.

9. The method as recited in claim 1 wherein said transformation is pre-programmed with information pertinent to a particular memory device.

10. The method as recited in claim 1 wherein said temperature sensor measures the temperature of said memory device.

11. The method as recited in claim 1 wherein said temperature sensor is a fixed temperature value known to be the temperature of said memory device during use.

12. The method as recited in claim 1 wherein said memory device is a flash memory device.

13. A memory device programming system comprising:

an integrated circuit comprising a memory device;

a temperature sensor disposed near said integrated circuit, said temperature sensor for measuring the temperature of said memory device;

a processor coupled to said integrated circuit, said processor accessing a transformation and using said temperature provided by said temperature sensor to index said transformation to receive therefrom a programming time for said memory device based on a programming voltage and said temperature;

a voltage pump coupled to said integrated circuit, said voltage pump for applying said programming voltage to said memory device; and

a pulse width generator coupled to said integrated circuit and for measuring the programming time said programming voltage is to be applied to said memory device during programming thereof.

14. The system of claim 13 wherein said transformation is a memory table comprising time, voltage, and temperature variables for programming said memory device.

15. The system of claim 13 wherein said transformation is an equation for programming said memory device.

16. The system of claim 13 wherein said transformation is programmed at the testing stage of device manufacture.

17. The system of claim 16 wherein said integrated circuit further comprises said transformation.

18. The system of claim 13 wherein said processor is a microprocessor on a microcontroller programmable system on a chip (PSOC).

19. The system of claim 13 wherein said pulse width generator is programmed by said processor.

20. The system of claim 13 wherein said memory device is a flash memory device.

21. A memory device programming system comprising:

a programmable non-volatile memory device;

a temperature sensor measuring the temperature near said memory device;

a transformation comprising time, and temperature variables for programming said memory device;

a processor accessing said transformation with said temperature to obtain a programming time for said memory device as a function of a programming voltage and said temperature;

a voltage pump applying said voltage to said memory device; and

a pulse width generator applying said voltage to said memory device for said programming time.

22. The system of claim 21 wherein said transformation is pre-programmed.

23. The system of claim 21 wherein said transformation and said memory device are disposed on separate integrated circuits.

24. The system of claim 21 wherein said processor and said memory device are disposed on separate integrated circuits.

25. The system of claim 21 wherein said voltage pump and said memory device are disposed on separate integrated circuits.

26. The system of claim 21 wherein said clock and said memory device are disposed on separate integrated circuits.

27. The system of claim 21 wherein said memory device is a flash memory device.

28. The system of claim 21 wherein said memory device is a portion of a programmable system on a chip (PSOC).

29. The system of claim 21 wherein said temperature sensor is a fixed temperature value known to be the temperature of the memory during use.