Chip FT test method

Abstract

The present invention discloses a chip FT testing method, including designing a hardware strategy: dividing the FT test into a core startup board and a function detection board; the core startup board is used to transmit signals with the test console, load the core startup firmware, and securely boot the function detection firmware; the function detection board is used to securely store the function detection firmware; and designing a software strategy: implementing a hierarchical firmware startup strategy, a firmware security strategy, and a secure startup strategy during the FT test process; the hierarchical firmware startup strategy is used to accelerate test firmware downloads and function switching; the firmware security strategy is used to securely store the test firmware; and the secure startup strategy is used to create a secure test environment and secure authentication. The chip FT testing method provided by the present invention, through innovative FT testing process and strategy design, not only rapidly implements chip FT testing, but also has high reliability, good practicality, and is simple and convenient to implement.

Description

Technical Field

[0001] The present invention belongs to the field of chip testing, and in particular relates to a chip FT testing method. Background Art

[0002] With the development of economy and technology and the improvement of people's living standards, chips have been widely used in people's production and life, bringing endless convenience to people's production and life. Therefore, ensuring the stable and reliable operation of chips has become the research focus of chip manufacturers.

[0003] From chip design to the final release of the finished chip, multiple tests are required. Currently, during the FT test (Final Test) phase of the chip, most chip manufacturers outsource this process to the packaging and testing factory. However, the packaging and testing factory needs to develop separate testing for this part, which makes the cost of this part of the test higher. In addition, the separate development of the packaging and testing factory for different requirements has a certain development cycle. Moreover, due to the different understanding of chip modules and the technical level of developers, the packaging and testing factory generally finds it difficult to meet the high standards of chip manufacturers. Finally, when it comes to customization of multiple requirements, the packaging and testing factory generally finds it difficult to meet them in a timely and effective manner. Summary of the Invention

[0004] The object of the present invention is to provide a chip FT testing method which has high reliability, good practicability and is simple and convenient to implement.

[0005] The chip FT testing method provided by the present invention comprises the following steps:

[0006] S1. Design a hardware strategy: Divide the FT test into a core startup board and a function test board. The core startup board is used to communicate with the test console, load the core startup firmware, and securely boot the function test firmware. The function test board is used to securely store the function test firmware.

[0007] S2. Design software strategy: used to implement hierarchical firmware startup strategy, firmware security strategy, and secure startup strategy during the FT test process. The hierarchical firmware startup strategy is used to accelerate test firmware download and function switching; the firmware security strategy is used to achieve secure storage of test firmware; and the secure startup strategy is used to create a secure test environment and secure authentication.

[0008] The hardware design strategy specifically includes the following steps:

[0009] A. Download the core startup firmware from the core startup board and load it onto the FT test machine. The test signal is normal.

[0010] B. Use the burning tool to burn the function detection firmware to the function test board;

[0011] C. Install the functional test board onto the core startup board and start the FT test;

[0012] D. If the production requirements need to be switched, the new requirement test firmware will be burned into the new function test board, and the function test board will be replaced to realize the change of FT test requirements.

[0013] The hierarchical firmware startup strategy specifically includes the following steps:

[0014] The detection firmware is divided into core startup firmware and function detection firmware; the core startup firmware is used to start the chip and is temporarily downloaded when in use; the function detection firmware is used to detect the functional modules of the chip and output signals, and is pre-downloaded to the function detection board;

[0015] During startup, the core startup firmware is started first; after the core startup firmware is started, the startup environment is tested; after the test passes, the function test firmware is booted to start.

[0016] The firmware security policy specifically includes the following steps:

[0017] a. The chip manufacturer generates a firmware authentication key pair (K A ,K B );

[0018] b. The firmware authentication key K A Write the manufacturer information factor P into the core startup firmware, and write the core startup firmware into the core startup board;

[0019] c. Calculate the information digest H of the function detection firmware using the information digest algorithm, and then disperse it by the manufacturer information factor P. The dispersed information M1 is obtained as M1 = H||P; where || is the new information string M1 formed by combining H and P in a fixed sequence;

[0020] d. Use firmware authentication key K B Sign the dispersed information M1 and obtain the signature information S as S=Sign(K B ,M1); where Sign() is the key K B Sign M1;

[0021] e. Using firmware authentication key K A Disperse the manufacturer information factor P to obtain the distributed key K C for K A XOR algorithm with P; the obtained distributed key K C Distribute with signature information S to obtain encrypted information K D KD =ENC(K C ,S); where ENC() is the key K C Encrypt S;

[0022] f. Using encrypted information K D The startup information M2 of the function detection firmware and the firmware content M3 of the function detection firmware are encrypted to obtain the ciphertext information E as E=ENC(K D ,M2||M3);

[0023] g. Write the signature information S and ciphertext information E into the function detection board to implement information protection writing of the function detection board.

[0024] The secure boot strategy specifically includes the following steps:

[0025] (1) FT test machine start-up test;

[0026] (2) The core boot board turns on the chip power and the chip enters the RomBoot mode;

[0027] (3) The core boot board communicates with the chip through the serial port, downloads the core boot firmware to the chip's IRAM, runs it in the IRAM, and enters the core boot firmware security environment;

[0028] (4) After the core startup firmware initializes the secure operating environment, it communicates with the function detection board and reads the function detection firmware information stored in the function detection board;

[0029] (5) The core boot firmware uses the firmware authentication key K A and the manufacturer information factor P to obtain the distributed key K C (Right now: ), the obtained distributed key K C Distribute with signature information S to obtain encrypted information K D K D =ENC(K C ,S), using the encryption key K D Decrypt the function detection firmware information M and verify the signature; in the decryption process, M=DEC(K D ,E), where M is the key K D The decrypted content of information E is the startup information M2 of the function detection firmware and the firmware content M3 of the function detection firmware. DEC() is the decryption operation; the signature verification process is Verify(K A ,M3,S), where Verify() is K A Perform signature verification on M3 information to see if the result is S. If so, the verification passes; otherwise, the verification fails.

[0030] (6) The core boot firmware clears the temporary key K C and K D ;

[0031] (7) Determine whether the function detection firmware information is correct:

[0032] If it is correct, the core startup firmware will boot the function detection firmware into the startup information area for startup;

[0033] If it is incorrect, the error information of the FT test machine will be reported and the test will end;

[0034] (8) After the function detection firmware is started, the core startup firmware boot area is cleared and the firmware authentication key K of the core startup firmware is destroyed A and manufacturer information factor P;

[0035] (9) The functional detection firmware performs FT test on the chip according to the detection sequence and sends the test results to the FT test machine.

[0036] The secure boot strategy further includes the following steps:

[0037] (10) If the FT test task needs to be changed, replace the function detection board and repeat steps (1) to (9) to complete the corresponding test.

[0038] The chip FT testing method provided by the present invention not only quickly realizes chip FT testing through an innovative FT testing process and strategy design, but also has high reliability, good practicality, and is simple and convenient to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0040] like Figure 1 The figure shows a schematic flow chart of the method of the present invention: the chip FT testing method provided by the present invention comprises the following steps:

[0041] S1. Design a hardware strategy: Divide the FT test into a core startup board and a function test board. The core startup board is used to communicate with the test console, load the core startup firmware, and securely boot the function test firmware. The function test board is used to securely store the function test firmware.

[0042] In specific implementation, designing a hardware strategy includes the following steps:

[0043] A. Download the core startup firmware from the core startup board and load it onto the FT test machine. The test signal is normal.

[0044] B. Use the burning tool to burn the function detection firmware to the function test board;

[0045] C. Install the functional test board onto the core startup board and start the FT test;

[0046] D. If the production requirements need to be switched, the new requirement test firmware will be burned into the new function test board, and the function test board will be replaced to realize the change of FT test requirements;

[0047] S2. Design software strategies: These strategies are used to implement hierarchical firmware boot strategies, firmware security strategies, and secure boot strategies during FT testing. The hierarchical firmware boot strategies accelerate test firmware downloads and function switching; the firmware security strategies enable secure storage of test firmware; and the secure boot strategies create a secure test environment and facilitate secure authentication.

[0048] In specific implementation, the hierarchical firmware startup strategy includes the following steps:

[0049] The detection firmware is divided into core startup firmware and function detection firmware; the core startup firmware is used to start the chip and is temporarily downloaded when in use; the function detection firmware is used to detect the functional modules of the chip and output signals, and is pre-downloaded to the function detection board;

[0050] During startup, the core startup firmware is started first. After the core startup firmware is started, the startup environment is tested. After the test passes, the function test firmware is then started.

[0051] The firmware security policy is a strategy that enables secure storage between the core startup firmware and the function detection firmware. That is, the core startup firmware does not contain core technical code and only provides a trusted environment for the function detection firmware to run. Because the function detection firmware contains core code, it needs to be stored confidentially and has the ability to destroy the core startup firmware key during runtime. The specific steps include:

[0052] a. The chip manufacturer generates a firmware authentication key pair (K A ,K B );

[0053] b. The firmware authentication key K A Write the manufacturer information factor P into the core startup firmware, and write the core startup firmware into the core startup board;

[0054] c. Calculate the information digest H of the function detection firmware using the information digest algorithm, and then disperse it by the manufacturer information factor P. The dispersed information M1 is obtained as M1 = H||P; where || is the new information string M1 formed by combining H and P in a fixed sequence;

[0055] d. Use firmware authentication key K BSign the dispersed information M1 and obtain the signature information S as S=Sign(K B ,M1); where Sign() is the key K B Sign M1;

[0056] e. Using firmware authentication key K A Disperse the manufacturer information factor P to obtain the distributed key K C for K A XOR algorithm with P; the obtained distributed key K C Distribute with signature information S to obtain encrypted information K D K D =ENC(K C ,S); where ENC() is the key K C Encrypt S;

[0057] f. Using encrypted information K D The startup information M2 of the function detection firmware and the firmware content M3 of the function detection firmware are encrypted to obtain the ciphertext information E as E=ENC(K D ,M2||M3);

[0058] g. The signature information S and ciphertext information E are written to the functional detection board to achieve information protection for the functional detection board;

[0059] The secure boot strategy is divided into the creation of a secure environment for the core boot firmware, the security authentication of the functional detection firmware, and the key destruction process. The specific steps include the following:

[0060] (1) FT test machine start-up test;

[0061] (2) The core boot board turns on the chip power and the chip enters the RomBoot mode;

[0062] (3) The core boot board communicates with the chip through the serial port, downloads the core boot firmware to the chip's IRAM, runs it in the IRAM, and enters the core boot firmware security environment;

[0063] (4) After the core startup firmware initializes the secure operating environment, it communicates with the function detection board and reads the function detection firmware information stored in the function detection board;

[0064] (5) The core boot firmware uses the firmware authentication key K A and the manufacturer information factor P to obtain the distributed key K C (Right now: ), the obtained distributed key K C Distribute with signature information S to obtain encrypted information KD K D =ENC(K C ,S), using the encryption key K D Decrypt the function detection firmware information M and verify the signature; in the decryption process, M=DEC(K D ,E), where M is the key K D The decrypted content of information E is the startup information M2 of the function detection firmware and the firmware content M3 of the function detection firmware. DEC() is the decryption operation; the signature verification process is Verify(K A ,M3,S), where Verify() is K A Perform signature verification on M3 information to see if the result is S. If so, the verification passes; otherwise, the verification fails.

[0065] (6) The core boot firmware clears the temporary key K C and K D ;

[0066] (7) Determine whether the function detection firmware information is correct:

[0067] If it is correct, the core startup firmware will boot the function detection firmware into the startup information area for startup;

[0068] If it is incorrect, the error information of the FT test machine will be reported and the test will end;

[0069] (8) After the function detection firmware is started, the core startup firmware boot area is cleared and the firmware authentication key K of the core startup firmware is destroyed A and manufacturer information factor P;

[0070] (9) The functional test firmware performs FT test on the chip according to the test sequence and sends the test results to the FT test machine;

[0071] (10) If the FT test task needs to be changed, replace the function detection board and repeat steps (1) to (9) to complete the corresponding test.

Claims

1. A chip FT testing method, comprising the following steps: S1. Design a hardware strategy: Divide the FT test into a core startup board and a functional test board. The core startup board is used to communicate with the test console, load the core startup firmware, and securely boot the functional test firmware. The function detection board is used for secure storage of function detection firmware; S2. Design software strategies: These strategies are used to implement hierarchical firmware boot strategies, firmware security strategies, and secure boot strategies during FT testing. The hierarchical firmware boot strategies accelerate test firmware downloads and function switching; the firmware security strategies enable secure storage of test firmware; and the secure boot strategies create a secure test environment and facilitate secure authentication. The firmware security policy specifically includes the following steps: a. The chip manufacturer generates a firmware authentication key pair (K A ,K B ); b. The firmware authentication key K A Write the manufacturer information factor P into the core startup firmware, and write the core startup firmware into the core startup board; c. Calculate the information digest H of the function detection firmware using the information digest algorithm, and then disperse it by the manufacturer information factor P. The dispersed information M1 is obtained as M1 = H||P; where || is the new information string M1 formed by combining H and P in a fixed sequence; d. Use firmware authentication key K B Sign the dispersed information M1 and obtain the signature information S as S=Sign(K B ,M1); where Sign() is the key K B Sign M1; e. Using firmware authentication key K A Disperse the manufacturer information factor P to obtain the distributed key K C for K A XOR algorithm with P; the obtained distributed key K C Distribute with signature information S to obtain encrypted information K D K D =ENC(K C ,S); where ENC() is the key K C Encrypt S; f. Using encrypted information K D The startup information M2 of the function detection firmware and the firmware content M3 of the function detection firmware are encrypted to obtain the ciphertext information E as E=ENC(K D ,M2||M3); g. Write the signature information S and ciphertext information E into the function detection board to implement information protection writing of the function detection board.

2. The chip FT test method according to claim 1, characterized in that The hardware design strategy specifically includes the following steps: A. Download the core startup firmware from the core startup board and load it onto the FT test machine. The test signal is normal. B. Use the burning tool to burn the function detection firmware to the function test board; C. Install the functional test board onto the core startup board and start the FT test; D. If the production requirements need to be switched, the new requirement test firmware will be burned into the new function test board, and the function test board will be replaced to realize the change of FT test requirements.

3. The chip FT testing method according to claim 2, characterized in that The hierarchical firmware startup strategy specifically includes the following steps: The detection firmware is divided into core startup firmware and function detection firmware; the core startup firmware is used to start the chip and is temporarily downloaded when in use; the function detection firmware is used to detect the functional modules of the chip and output signals, and is pre-downloaded to the function detection board; During startup, the core startup firmware is started first; after the core startup firmware is started, the startup environment is tested; after the test passes, the function test firmware is booted to start.

4. The chip FT testing method according to claim 1, characterized in that The secure boot strategy specifically includes the following steps: (1) FT test machine start-up test; (2) The core boot board turns on the chip power and the chip enters the RomBoot mode; (3) The core boot board communicates with the chip through the serial port, downloads the core boot firmware to the chip's IRAM, runs it in the IRAM, and enters the core boot firmware security environment; (4) After the core startup firmware initializes the secure operating environment, it communicates with the function detection board and reads the function detection firmware information stored in the function detection board; (5) The core boot firmware uses the firmware authentication key K A and the manufacturer information factor P to obtain the distributed key K C , the obtained distributed key K C Distribute with signature information S to obtain encrypted information K D K D =ENC(K C ,S), using the encryption key K D Decrypt the function detection firmware information M and verify the signature; in the decryption process, M=DEC(K D ,E), where M is the key K D The decrypted content of information E is the startup information M2 of the function detection firmware and the firmware content M3 of the function detection firmware. DEC() is the decryption operation; the signature verification process is Verify(K A ,M3,S), where Verify() is K A Perform signature verification on M3 information to see if the result is S. If so, the verification passes; otherwise, the verification fails. (6) The core boot firmware clears the temporary key K C and K D ; (7) Determine whether the function detection firmware information is correct: If it is correct, the core startup firmware will boot the function detection firmware into the startup information area for startup; If it is incorrect, the error information of the FT test machine will be reported and the test will end; (8) After the function detection firmware is started, the core startup firmware boot area is cleared and the firmware authentication key K of the core startup firmware is destroyed A and manufacturer information factor P; (9) The functional detection firmware performs FT test on the chip according to the detection sequence and sends the test results to the FT test machine.

5. The chip FT testing method according to claim 4, characterized in that The secure boot strategy further includes the following steps: (10) If the FT test task needs to be changed, replace the function detection board and repeat steps (1) to (9) to complete the corresponding test.

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