Memory device with data security in a processor

• US 7,761,717 B2
• Filed: 07/10/2002
• Issued: 07/20/2010
• Est. Priority Date: 07/10/2001
• Status: Active Grant

• Current Assignee: MaxLinear Communications, LLC (f/k/a Entropic Communications, LLC) (Maxlinear Incorporated)
• Original Assignee: Trident Microsystems Limited (Avnet Incorporated)
• Inventors: Ritter, Joachim, Möller, Peter, Zimmermann, Steffen, Mijovic, Zoran, Jünke, Manfred
• Primary Examiner(s): Moorthy; Aravind K
• Application Number:
  US10/193,659
• Publication Number:
  US 20030014653A1
• Time in Patent Office: 2,932 Days
• Field of Search: 713/189
• US Class Current: 713/189
• CPC Class Codes: G06F 21/572 Secure firmware programming, e.g. of basic input output system [BIOS]
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories

Abstract

A memory device containing data to be protected is integrated with a microprocessor and includes a first and a second memory portion with different accessibilities. The integration of the memory device on the same integrated circuit (IC) or chip as the microprocessor permits a combination of protective hardware and software measures that are not possible with a memory device that is on a different IC than the microprocessor. The first memory portion holds an initialization program that also serves as a boot program during decryption, and the second memory portion holds a user program, for example, a program for decrypting and/or decoding received data. Such data may be, for example, audio data encoded according to the MP3 standard and encrypted with a secret or public password against unauthorized reception.

Claims

1. An integrated circuit, comprising:

a processor;

a plurality of interfaces that provide external access to the integrated circuit, the plurality of interfaces comprising a USB interface, a JTAG interface and a parallel interface; and

a non-volatile memory device partitioned into a plurality of memory portions including a first memory portion and a second memory portion, where the first memory portion includes initialization executable program instructions that are executed upon power-up of the integrated circuit, and where the second memory portion includes (i) a first password, (ii) a second password, (iii) program control register data associated with enabling or disabling of the plurality of interfaces, and (iv) executable program instructions for encrypting or decrypting data, where the first and second passwords are associated with access by a user to the executable program instructions;

where bit locations of the program control register data associated with the plurality of interfaces are hardwired within the integrated circuit with interface control circuitry, such that upon a reset of the processor the bit locations of the program control register data are read by the interface control circuitry to determine which of the plurality of interfaces should be enabled based upon uniquely associated control bits in the program control register data.

2. The memory device of claim 1, where the plurality of interfaces comprises a first group of interfaces that comprise data interfaces that are independent of the processor.

3. The memory device of claim 1, where the plurality of interfaces comprises a second group of interfaces that comprise data interfaces that are both independent of the processor and controllable by the processor.

4. The memory device of claim 1, where the memory device comprises a random access memory device.

5. The memory device of claim 1, where the memory device comprises a flash memory device.

6. The memory device of claim 1, where the first and second memory portions are erasable by global erase information.

7. The memory device of claim 6, where the global erase information can be initiated by a predetermined configuration of levels at predetermined terminals of the processor.

8. The memory device of claim 7, where the predetermined terminals are inaccessible from outside of the memory device.

9. The memory device of claim 1, where one of the first and the second memory portions further comprises a protection control register, where in the event of a program update, disabling information present in the protection control register remains in the protection control register if the program update includes disabling information for the one of the plurality of data interfaces.

10. The memory device of claim 1, where a user program is stored in one of the first and second memory portions.

11. The memory device of claim 10, where the user program stored in one of the first and second memory portions includes a programmable protection bit that prevents erasure of the memory device.

12. An integrated circuit, comprising:

a processor;

a plurality of interfaces that provide external access to the integrated circuit; and

a non-volatile memory device partitioned into a plurality of memory portions including a first memory portion and a second memory portion, where the first memory portion includes initialization executable program instructions that are executed upon power-up of the integrated circuit, and where the second memory portion includes (i) a first password, (ii) a second password, (iii) program control register data associated with enabling or disabling of the plurality of interfaces and (iv) executable program instructions for encrypting or decrypting data, where the first and second passwords are associated with access by a user to the executable program instructions;

where bit locations of the program control register data associated with the plurality of interfaces are hardwired within the integrated circuit with interface control circuitry, such that upon a reset of the processor the bit locations of the program control register data are input to the interface control circuitry to determine which of the plurality of interfaces should be enabled based upon uniquely associated control bits in the program control register data.

13. The memory device of claim 12, where one of the plurality of first interfaces is independent of the processor.

14. The memory device of claim 12, where the first memory portion stores an initialization program.

15. The memory device of claim 12, where the second memory portion stores a user program that is selectively updatable.

16. An integrated circuit, comprising:

a processor;

a plurality of interfaces in communication with the processor, the plurality of interfaces providing external access to the integrated circuit; and

a non-volatile memory partitioned into a plurality of memory portions including a first memory portion and a second memory portion, the first memory portion including initialization executable program instructions executable upon power-up of the integrated circuit, the second memory portion including

a first password;

a second password, where each of the first and the second passwords have a first type of access and are associated with user access to the executable program instructions;

program control register data associated with enabling or disabling of the plurality of interfaces; and

executable program instructions associated with encrypting or decrypting data;

where bit locations of the program control register data associated with the plurality of interfaces are hardwired within the integrated circuit with interface control circuitry, such that upon a reset of the processor the bit locations of the program control register data are read by the interface control circuitry to determine which of the plurality of interfaces should be enabled based upon uniquely associated control bits in the program control register data.