Device and method capable of verifying program operation of non-volatile memory and method card including the same

• US 20070168793A1
• Filed: 01/05/2007
• Published: 07/19/2007
• Est. Priority Date: 01/09/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Seo, Kyung-Duck
• Granted Patent: US 7,992,009 B2
• Time in Patent Office: Days
• US Class Current: 714/724
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 21/51 at application loading time, e.g. accepting, rejecting, starting or inhibiting executable software based on integrity or source reliability
• CPC Class Codes: G11C 16/22 Safety or protection circuits preventing unauthorised or accidental access to memory cells
• CPC Class Codes: G11C 2029/0411 Online error correction

Abstract

A method of verifying programming of an integrated circuit card includes transferring program data to a page buffer of a non-volatile memory, copying the program data to a buffer memory, calculating a first checksum value with respect to program data in the buffer memory, updating the program data in the buffer memory by copying the program data of the page buffer to the buffer memory, calculating a second checksum value with respect to updated program data in the buffer memory, comparing the first checksum value and the second checksum value, and determining, based on the comparison result, whether the program data of the page buffer is tampered.

Claims

1. A method of verifying programming of an integrated circuit card comprising:

transferring program data to a page buffer of a non-volatile memory;

copying the program data to a buffer memory;

calculating a first checksum value with respect to the program data in the buffer memory;

updating the program data in the buffer memory by copying the program data of the page buffer to the buffer memory;

calculating a second checksum value with respect to updated program data in the buffer memory;

comparing the first checksum value and the second checksum value; and

determining, based on the comparison result, whether the program data of the page buffer is tampered.

2. The method of claim 1, wherein a random access memory of the integrated circuit card is provided with the program data which is copied to the buffer memory after the transferring of data to the page buffer of the non-volatile memory is completed.

3. The method of claim 1, further comprising:

terminating a program procedure when the first checksum value and the second checksum value do not coincide with each other.

4. The method of claim 3, further comprising:

generating an interrupt when the first checksum value and the second checksum value do not coincide with each other.

5. The method of claim 3, further comprising:

generating external attack detection information when the first checksum value and the second checksum value do not coincide with each other.

6. The method of claim 1, further comprising:

copying page data from a selected page of the non-volatile memory to the buffer memory, when the first checksum value and the second checksum value coincide with each other, the program data being to be stored in the selected page; and

programming the program data of the buffer memory to the selected page.

7. The method of claim 6, further comprising:

updating the buffer memory with program data stored in the random access memory of the integrated circuit chip while the program data of the buffer memory is programmed in the selected page; and

calculating a third checksum value with respect to data of the buffer memory.

8. The method of claim 7, further comprising:

calculating a fourth checksum value with respect to data of the selected page directly via a cyclic redundancy check calculation logic after a program operation for the program data is completed; and

determining a pass/fail of the program operation based on whether the third checksum value corresponds to the fourth checksum value.

9. The method of claim 8, further comprising:

terminating a program procedure when the third checksum value corresponds to the fourth checksum value.

10. The method of claim 8, further comprising:

performing a re-program operation when the third checksum value does not correspond to the fourth checksum value.

11. The method of claim 10, wherein at the re-program operation, no calculation operation for the third checksum value is performed.

12. The method of claim 8, further comprising:

setting a flag bit informing a generation of a program error and terminating the program-operation when no third checksum value corresponds to the fourth checksum value.

13. An integrated circuit card comprising:

a random access memory;

a non-volatile memory; and

a control unit for controlling the random access memory and the non-volatile memory,

wherein at a program operation, after transferring program data in the RAM to a page buffer of the non-volatile memory, the control unit determines whether the program data of the page buffer is tampered and enables the program data of the page buffer to be stored in a selected page of the non-volatile memory according to the determination.

14. The integrated circuit chip of claim 13, wherein the control unit comprises:

a buffer memory;

a cyclic redundancy check calculation logic;

a random delay control logic for copying the program data of the random access memory to the buffer memory after the program data is transferred to the page buffer; and

a data copy and control logic for controlling the cyclic redundancy check calculation logic so as to calculate a first checksum value with respect to the program data of the buffer memory, after the program data is copied to the buffer memory from the random access memory.

15. The method of claim 14, wherein after the first checksum value is calculated, the data copy and control logic controls the non-volatile memory so that the program data of the page buffer is transferred to the buffer memory.

16. The integrated circuit chip of claim 15, wherein after the program data of the page buffer is transferred to the buffer memory, the data copy and control logic controls the cyclic redundancy check calculation logic so as to calculate a second checksum value with respect to the program data of the buffer memory from the page buffer.

17. The integrated circuit card of claim 16, wherein the control unit further comprises:

a cyclic redundancy check register for storing the first checksum value and the second checksum value;

a comparator controlled by the data copy and control logic, for determining whether the first checksum value is identical to the second checksum value; and

a correction/detection control logic for generating a program end signal when the comparison result indicates that the first checksum value is not identical to the second checksum value.

18. The integrated circuit card of claim 17, wherein when the program end signal is generated, the correction/detection control logic generates an external attack detection flag signal informing that the program data of the page buffer is tampered.

19. The integrated circuit card of claim 17, wherein the program end signal is generated, the correction/detection control logic generates an interrupt.

20. The integrated circuit card of claim 17, wherein when the comparison result indicates that the first checksum value is identical to the second checksum value,

the data copy and control logic controls the non-volatile memory so that data of a selected page in the non-volatile memory is copied to the buffer memory.

21. The integrated circuit card of claim 20, wherein after data of a selected page in the non-volatile memory is copied to the buffer memory,

the data copy and control logic controls the non-volatile memory so that the program data of the page buffer is programmed in the selected page.

22. The integrated circuit card of claim 21, wherein while a program operation is carried out,

the data copy and control logic updates the buffer memory with the program data of the random access memory.

23. The integrated circuit card of claim 22, wherein the data copy and control logic controls the cyclic redundancy check calculation logic so as to calculate a third checksum value with respect to data of the buffer memory, the third checksum value being stored in the register.

24. The integrated circuit card of claim 23, wherein when the program operation is completed,

the data copy and control logic controls the non-volatile memory so that data of the selected page is copied to the buffer memory, and then controls the cyclic redundancy check calculation logic so as to calculate a fourth checksum value with respect to data of the buffer memory, the fourth checksum value being stored in the register.

25. The integrated circuit card of claim 24, wherein the data copy and control logic controls the comparator to judge whether the third checksum value is identical to the fourth checksum value.

26. The integrated circuit card of claim 25, wherein when the third checksum value is identical to the fourth checksum value, the correction/detection control logic generates a program end signal.

27. The integrated circuit card of claim 25, wherein when the third checksum value is not identical to the fourth checksum value, the correction/detection control logic generates a re-program signal so that program data of the page buffer is re-programmed.

28. The integrated circuit card of claim 27, wherein at the re-program operation, a calculation operation for the third checksum value is not carried out.

29. The integrated circuit card of claim 25, wherein when the third checksum value is not identical to the fourth checksum value, the correction/detection control logic generates a flag signal informing a program error generation and a program end signal informing an end of the program operation.

30. The integrated circuit card of claim 15, wherein the integrated circuit card comprises a smart card.