Codelets

• US 6,736,325 B1
• Filed: 01/13/1999
• Issued: 05/18/2004
• Est. Priority Date: 01/22/1998
• Status: Expired due to Term

• Current Assignee: Mondex International Ltd. (MasterCard Incorporated)
• Original Assignee: Mondex International Ltd. (MasterCard Incorporated)
• Inventors: Peacham, Anthony David
• Primary Examiner(s): Maung, Zarni
• Assistant Examiner(s): OPIE, GEORGE L
• Application Number:
  US09/229,714
• Time in Patent Office: 1,952 Days
• Field of Search: 712/209, 712/211, 717/136-148, 235/492, 235/487
• US Class Current: 235/492
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/3552 Downloading or loading of personalisation data
• CPC Class Codes: G06Q 20/3576 Multiple memory zones on card
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system

Abstract

A system and method for efficiently storing programming instructions in a microprocessor based system where codelets which include program instructions written in a non-native programming language (such as MEL or C) are stored in a read only portion of memory. The location of the codelets are stored in an address table which is accessed by an operating system when an application calls the codelet during execution. At that time, the microprocessor accesses the codelet instructions until the codelet function is complete. By storing codelets in read only memory which is cheaper and takes up much less physical space than alterable memory (such as EEPROM), more programming instructions can be stored in the same amount of physical space. Additionally, since codelets are written in non-native programming languages, they become platform independent since they can be compiled by different compilers to run on any platform.

Claims

1. An integrated circuit card comprising:

a read-only memory;

an alterable memory;

a microprocessor coupled to said read-only and alterable memory;

an operating system stored in said read-only memory, wherein said operating system is executed by said microprocessor;

at least one application stored in said alterable memory; and

a codelet stored in said read-only memory and comprising at least one non-native program instruction written in a programming language capable of being converted for execution by said microprocessor.

2. The integrated circuit card of claim 1, wherein said alterable memory comprises an EEPROM.

3. The integrated circuit card of claim 1, wherein one of said application'"'"'s program instructions calls said codelet.

4. The integrated circuit card of claim 1, further comprising an address table for storing said memory address and identifier of said stored codelet.

5. The integrated circuit card of claim 4, wherein said address table is stored in said alterable memory.

6. The integrated circuit card of claim 4, wherein said operating system executes said codelet by looking up said codelet'"'"'s memory address in said address table using said codelet'"'"'s identifier.

7. The integrated circuit card of claim 1, further including a primitive stored in said read-only memory.

8. The integrated circuit card of claim 7, wherein said primitive verifies said codelet'"'"'s presence on said IC card.

9. The IC card of claim 8, further including a register indicative of said codelet'"'"'s presence.

10. The integrated circuit card of claim 7, wherein said codelet executes said primitive.

11. The integrated circuit card of claim 10, wherein said execution of said primitive uses an address table look up to determine said primitive'"'"'s memory location.

12. A method for efficiently storing programming instructions in a microprocessor system including read-only memory and alterable memory comprising the steps of:

storing an operating system in said read-only memory;

storing at least one application written in a non-native computer language in said alterable memory;

storing a codelet comprising program instructions written in a non-native computer language which is a programming language capable of being converted for execution by said microprocessor, in said read-only memory; and

storing said codelet'"'"'s address location in an address table;

wherein said codelet is accessed by said operating system using said address table, and further wherein said read-only memory and said alterable memory are part of an integrated circuit card.

13. The method of claim 12, wherein said alterable memory comprises EEPROM.

14. The method of claim 12, wherein one of said application'"'"'s program instructions calls said codelet.

15. The method of claim 12, wherein said address table is stored in said alterable memory.

16. The method of claim 15, wherein said operating system executes said codelet by looking up said codelet'"'"'s memory address in said address table.

17. The method of claim 12, wherein said address table is stored in said read-only memory.

18. The method of claim 12, further including the step of storing a primitive in said read-only memory.

19. The method of claim 12, wherein said non-native computer language of said at least one application is said non-native computer language of said codelet.

20. The method of claim 12, further including the step of verifying the presence of said codelet on said IC card.

21. A system for efficiently storing programming instructions in a microprocessor system comprising:

a read-only memory storing an operating system and at least one codelet, wherein said codelet comprises program instructions written in a non-native programming language requiring interpretation by said operating system; and

an alterable memory storing at least one application comprising program instructions and data and an address table;

wherein said memory address and identifier of said codelet is stored in said address table and said codelet is accessed by said at least one application during said application'"'"'s execution, and further wherein said microprocessor system resides on an integrated circuit card.

22. The system of claim 21, wherein said codelet'"'"'s program instruction utilizes said application'"'"'s data.

23. The system of claim 21, further including a means for verifying said codelet'"'"'s presence in said read-only memory.

24. The system of claim 21, wherein said operating system executes said codelet by looking up said codelet'"'"'s memory address in said address table using said codelet'"'"'s identifier.