JP2004246699A - System lsi relieved of defect, compiler program for firmware mounted on system lsi, and shipping method for shipping system lsi - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relieve a system LSI device even if any defect exists in a built-in memory. <P>SOLUTION: The system LSI has a CPU for executing a given firmware program, and the memory in which the firmware program is installed at a boot. The memory 12 has an installation area and a work area accessed by the installed firmware program, and the installed firmware program avoid accessing a defective area in the work area. A plurality of types of firmware programs that avoid accessing particular areas in the work area of the memory are prepared in connection with the particular areas. If a defect is detected in the work area at the shipping stage of the system LSI, the firmware program in connection with the particular area having the defect is selected and shipped together with the system LSI. The firmware program installed in the built-in memory of the system LSI thus avoids accessing the area including the defect when accessing the work area of the memory. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a system LSI that has repaired a defect in a memory area, a compiler program for firmware mounted on the system LSI, and a shipping method for shipping the system LSI.
[0002]
[Prior art]
In recent years, system LSIs for specific applications have become widespread. For example, digital AV devices such as a DVD recorder player and an HD recorder player are equipped with a system LSI dedicated to MPEG decoding. A printer or the like is equipped with a system LSI for performing image processing for expanding print data supplied from a host computer into image data for printing. Such a system LSI is an application-specific integrated circuit called an ASIC, in which a CPU, a RAM, a ROM, a macro having a specific function, and the like are embedded in a single chip. Such a system LSI is called a system-on-chip (SOC).
[0003]
Further, such a system LSI is stored in a common package together with an external large-capacity memory, for example, a DRAM. Such a device is called a system in package (SIP). These SOCs and SIPs are highly functional, highly integrated, and generally expensive.
[0004]
On the other hand, a memory device has been proposed in which, when a defective cell is included in a memory device, the memory device can be accessed except for a unit memory area including the defective cell (Patent Document 1).
[0005]
[Patent Document 1]
JP-A-11-25004
[Problems to be solved by the invention]
In a system LSI such as the above-described SOC or SIP, if a defect exists in a built-in memory or an external memory, the entire SOC or SIP becomes defective, resulting in a decrease in yield. It is desired to avoid such a decrease in the yield of expensive devices as much as possible.
[0007]
Accordingly, an object of the present invention is to provide a new system LSI that can be remedied even if a built-in memory has a defect in a system LSI such as SOC or SIP.
[0008]
Another object of the present invention is to provide a production method that can repair a built-in memory of a system LSI such as SOC or SIP even if the built-in memory has a defect.
[0009]
Still another object of the present invention is to provide a compiler program that can rescue a system LSI such as an SOC or SIP even if the built-in memory has a defect, even if the built-in memory has a defect.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is a system LSI having a CPU that executes a predetermined firmware program, and a memory in which the firmware program is installed at the time of startup. And a work area accessed by the installed firmware program, and the installed firmware program does not access a defective area in the work area.
[0011]
According to the first aspect of the present invention, a plurality of types of firmware programs that do not access a specific area of the work area of the memory are prepared corresponding to the specific area, and the firmware program is prepared at the stage of shipping the system LSI. When a defect is detected in the area, a firmware program corresponding to the specific area having the defect is selected and shipped together with the system LSI. Therefore, the firmware program installed in the internal memory of the system LSI does not access a defective area in accessing the work area of the memory.
[0012]
In the first aspect of the present invention, the memory in which the firmware program is installed is either built in a common chip with the CPU or built in a common package with the chip having the CPU. May be.
[0013]
Further, in the first aspect of the present invention, in a preferred embodiment, the selected firmware program is stored in a built-in firmware memory and shipped. Therefore, at the time of startup, the firmware program is downloaded from the firmware memory to the built-in memory and stored.
[0014]
In order to achieve the above object, a second aspect of the present invention is a system LSI having a CPU for executing a predetermined firmware program and a memory in which the firmware program is installed at the time of startup, wherein the memory is Having an installation area and a work area accessed by the installed firmware program, wherein the installed firmware program is installed in the work area when a defect exists in the installation area. It is characterized by that.
[0015]
In order to achieve the above object, a third aspect of the present invention is a method for testing a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup. Performing a step of detecting a defective area in the memory, and without accessing a specific area of the memory, from among a plurality of firmware programs generated corresponding to the specific area, Selecting a firmware program corresponding to a specific area including a defective area and shipping the selected firmware program together with the system LSI.
[0016]
In order to achieve the above object, a fourth aspect of the present invention relates to a firmware for a system LSI having a CPU for executing a predetermined firmware program and a memory in which the firmware program is installed at startup. In a compiler program for generating a program, a procedure of inputting and analyzing the firmware program, and a procedure of converting an access code to a defective area in the memory into an access code to the outside of the defective area and converting the code to an object code Are executed by a computer.
[0017]
By using the compiler program according to the fourth aspect of the present invention, it is possible to automatically generate a firmware program that can be installed even in a system LSI in which a defect is found in a memory in a shipping test. This can contribute to an improvement in the yield of LSI.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of protection of the present invention is not limited to the following embodiments, but extends to the inventions described in the claims and their equivalents.
[0019]
FIG. 1 is a diagram illustrating an example of a system LSI according to the present embodiment. This system LSI is an MPEG encoder mounted on digital AV equipment and the like. The system LSI 10 includes a CPU, a built-in memory 12 in which a firmware program to be executed by the CPU is installed, a memory controller 14, and a boot ROM in which a startup program for externally installing a firmware program at startup is stored. , Are connected via a built-in bus 11. Further, the system LSI 10 receives the video signal IN1 and encodes the encoded signal into the MPEG format, the audio signal IN2 receives and encodes the audio signal IN2, and multiplexes both encoded signals. It has a multiplex processing unit 20 and a PCI interface unit 22 that interfaces with an external PCI bus CI-BUS. The multiplexed MPEG encoded signal is output from the interphase unit 22 to an external bus.
[0020]
The system LSI is connected to the host computer 24 via a PCI bus PCI-BUS. In the host computer 24, an MPEG driver program 26 having a firmware program to be installed in the system LSI 10 is stored. When the power is turned on, the firmware program of the MPEG driver program 26 is installed in the internal memory 12 of the system LSI 10 in response to the execution of the start program. In the example of FIG. 1, the internal memory 12 is a synchronous DRAM (SDRAM).
[0021]
In the system LSI, when the power is turned on, a startup program in a built-in boot ROM is executed by the CPU, and accordingly, a firmware program included in the driver 16 is downloaded into the built-in memory 12. The firmware program installed by this download is thereafter executed one by one by the CPU, and the processes of the video encoding unit 16, the audio encoding unit 18, the multiplex processing unit 20, and the like are controlled.
[0022]
FIG. 2 is a chart showing an example of an address space of the system LSI of FIG. The address space and size shown in the table are assigned to the boot ROM, the SDRAM 12, the SDRAM interface controller 14, the video encoding unit 16, the multiplex processing unit 20, and the audio encoding unit 18 built in the system LSI. A space of addresses 0x80000000 to 0x87FFFFF is allocated to the SDRAM which is a built-in memory. In the address space, addresses 0x8000000 to 0x802CFFF are located in the area A where the firmware program is installed, and addresses 0x802D000 to 0x87FFFFF are located in the firmware program. Are assigned to the area B of the work area to be accessed.
[0023]
FIG. 3 is a diagram illustrating a configuration of the memory 12. FIG. 3A shows a case where no defect exists in the memory, and FIG. 3B shows a case where a defect exists in a specific area B2 of the area B of the memory. The memory 12 has an installation area A and a work area B, and the capacity of the installation area A is very small compared to the capacity of the work area B. Therefore, the work area B is divided into four areas B1 to B4, the divided areas B1 to B4 including the defective area are detected, and a firmware program that does not access the detected area is selected and attached to the system LSI or Stored and shipped.
[0024]
FIG. 4 is a diagram illustrating an example of a firmware program according to the present embodiment. FIG. 4A shows a case where there is no defect in the work memory area B of the memory 12, and FIG. 4B shows a case where there is a defect in the area B2 of the work memory area B of the memory 12. The work area B is equally divided into four as described above. Then, in a later-described shipping test of the system LSI, it is checked whether or not a defect exists in the work area B. In this example, it is assumed that no defect exists in the installation area A.
[0025]
When there is no defect in the memory 12, the firmware program F0 when there is no defect is installed in the installation area A. As shown in the figure, the firmware program F0 includes, for example, an addition operation code ADD for adding the value of the address a1 and the value of the address a2 in the area B1, and the value of the address a3 and the area in the area B2. It has a multiplication operation code MUX for multiplying the value of the address a4 in B3 and a jump instruction code JMP for jumping to the address x1 in the installation area A.
[0026]
If a defect is detected in the work area B of the memory 12, a firmware program that does not access the area containing the defect is installed. In the example of FIG. 4B, since a defect is detected in the area B2, the firmware program F2 for accessing the areas B1, B3, and B4 other than the area B2 is installed. In the firmware program F2, as shown in the figure, the multiplication operation code MUX of the program F0 is changed to a code for multiplying the value of the address a3 + d in the area B3 by the value of the address a4 + d in the area B4. Have been. Here, the address width d corresponds to the address width of the area B2 where the defect is detected.
[0027]
That is, if the access destination address of the firmware program F0 installed when no defect exists is equal to or larger than the address of the area B2 where the defect is detected, the access destination address is shifted by the address width d of the area B2. , Can be converted to a firmware program F2 that does not access the area B2. Such conversion is realized by a compiler program described later.
[0028]
FIG. 5 is a diagram illustrating another example of the firmware program according to the present embodiment. This firmware program FA is a program when a defect is detected in the installation area A of the memory 12. The firmware program must be uniformly installed in the address area after the start address of the installation area A of the memory 12 by executing the boot program in the boot ROM. Therefore, it is assumed that the very small capacity area A1 including the start address of the installation area A has no defect. Then, the firmware FA-i for initializing the firmware FA is installed in the small capacity area A1 by executing the activation program. This installation is possible when the driver 26 shown in FIG. 1 returns not the normal firmware but the initialization firmware FA-i in response to the installation command of the boot program.
[0029]
The initialization firmware FA-i has at least an instruction code INST for installing the firmware program FA at the start address dA + 1 and thereafter of the area B1, and an instruction code JMP for jumping to the start address dA + 1. Then, when the initialization firmware FA-i installed by the boot program in the boot ROM is executed, the installation command INST is executed only for the first time, and the firmware program FA is installed from the driver 26 into the area B1. . After the first time, the firmware program FA installed in the area B1 is executed by the jump instruction JMP of the initialization firmware FA-i.
[0030]
In the firmware program FA, the access destination addresses a1, a2, a3, and a4 of the firmware program F0 in FIG. 4A are converted into a1 + d, A2 + d, A3 + d, and A4 + d, respectively. x1 + Ad. Here, d is the address width of the area B1, and dA is the address width of the area A. That is, the program address x1 is shifted by the address width dA of the area A where the defect exists, and the access destination addresses a1 to a4 are shifted by the address width d of the area B1 where the firmware program FA is installed.
[0031]
FIG. 6 is a flowchart showing a shipment process of the system LSI according to the present embodiment. A system LSI is manufactured in a chip manufacturing process S1, and an operation test of its built-in memory is performed in a test / selection process S2 at the time of shipment. By this test, it is detected which area of the built-in memory 12 has a defect, and a chip having no defect and a chip having a defect are sorted out. ＢB4, selected according to the area A.
[0032]
On the other hand, a firmware program to be installed in the system LSI is generated in the programming step S3, and the firmware program FW, which is the source code, is converted into an object code in the compiling step S4. In the compiling step S4, the firmware programs are converted into six types of firmware program F0, F1 to F4, and FA object codes corresponding to the presence / absence of a defect and the area where the defect exists. The converted program is registered in the database (S5).
[0033]
Each of the system LSIs selected in the test / selection step S2 is associated with an object code of a corresponding firmware program (S6), and shipped together with the associated firmware program (S7). Therefore, the user who has purchased this system LSI stores the attached firmware program in the driver 26 and installs it in the host computer 24. As a result, when the system LSI starts up, the corresponding firmware program is downloaded and stored in the internal memory 12.
[0034]
FIG. 7 is a flowchart illustrating a procedure of a compiler program according to the present embodiment. This compiler program is executed by a computer (not shown) in a compiling step S4 in FIG. 6, and converts the source code of the firmware program into object code.
[0035]
First, the compiler program inputs a program to be compiled (S10), and further inputs defect information (S12). In the example described above, there are six types of defect information: no defect in the memory 12 of the system LSI, defects in the areas B1 to B4, and defects in the area A. Next, the compiler program analyzes the syntax of the input compilation target program (S14), and determines whether or not the defect information has a defect (S16). If there is no defect, it simply converts the defect information into object code (S20). . If there is a defect, the address is converted so that the area containing the defect is not used, and is converted into an object code (S21). An example of address conversion is as shown in FIGS.
[0036]
By executing the above-mentioned compile processing for all types of defect information, six types of firmware program object codes are generated. The generated six types of object codes are registered in the database as described above.
[0037]
FIG. 8 is a diagram illustrating an example of a system LSI according to the second embodiment. In this example, the system LSI 10 has a nonvolatile memory 28 that stores a firmware program installed in the built-in memory 12. The non-volatile memory 28 is a memory to which a firmware program can be written and which can hold the firmware program even when the power is turned off. For example, a flash memory is used. Other configurations are the same as those of the system LSI of FIG. Accordingly, the firmware program is not supplied from the host computer 24.
[0038]
In this system LSI, when the power is turned on, the CPU executes the start program in the boot ROM, and downloads and stores the firmware program in the non-volatile memory 28 in the installation area A of the internal memory 12. Thereafter, the stored firmware program is executed one by one by the CPU.
[0039]
FIG. 9 is a chart showing an example of the address space of the system LSI of FIG. In this example, in addition to the address space of the boot ROM, the address space of the nonvolatile memory is also allocated. The address space of the built-in memory composed of the SDRAM and other circuits is the same as the example of FIG.
[0040]
Therefore, also in the case of the second embodiment, the respective firmware programs are stored in the built-in memory 12 according to the area where the built-in memory 12 has a defect or not, and in the case where the built-in memory 12 is defective. It is downloaded and stored in the installation area A. An example of the firmware program is the same as the example shown in FIGS. However, the selected firmware program is stored in the nonvolatile memory 28 in the system LSI at the time of shipment.
[0041]
FIG. 10 is a flowchart illustrating a system LSI shipping process according to the second embodiment. This shipping process differs from the shipping process of FIG. 6 in that the corresponding firmware registered in the database is stored in the nonvolatile memory 28 of the system LSI selected in the test / selection step S2 in the firmware storage step S8. Is done. Other steps are the same as those in FIG.
[0042]
The system LSI shipped in this way is mounted on a digital AV device or the like by a user. When the power of the device is turned on, a firmware program in a non-volatile memory built in the system LSI is downloaded to the built-in memory 12, and thereafter, the downloaded firmware program is executed by the CPU.
[0043]
In the embodiment described above, the memory 12 for downloading and storing the firmware is built in the same chip as the system LSI. However, the memory 12 may be mounted on a common package in a different chip from the system LSI.
[0044]
Further, in the above embodiment, the firmware program corresponding to the defective area of the built-in memory is shipped attached to the system LSI or stored in the firmware memory in the system LSI. The present invention is not limited to this, and all kinds of firmware programs may be shipped attached to a system LSI or stored in a firmware memory. In this case, information for identifying whether the firmware program should be installed is stored in a nonvolatile memory or the like in the system LSI. Then, the boot program in the boot ROM refers to the identification information and downloads and stores the corresponding firmware program in the internal memory 12.
[0045]
As described above, the embodiments are summarized as follows.
[0046]
(Supplementary Note 1) In a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup,
The memory has the installation area and a work area accessed by the installed firmware program, and the installed firmware program does not access a defective area in the work area. System LSI.
[0047]
(Supplementary Note 2) In a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup,
The memory has the installation area and a work area accessed by the installed firmware program,
The system LSI, wherein the installed firmware program is installed in the work area when a defect exists in the installation area.
[0048]
(Supplementary Note 3) In Supplementary note 1 or 2,
Further, the firmware program is attached to the system LSI,
A system LSI, wherein the attached firmware program is downloaded from outside the system LSI.
[0049]
(Supplementary Note 4) In Supplementary Note 1 or 2,
Furthermore, it has a firmware storage memory storing the firmware program,
A system LSI, wherein the firmware program is downloaded from the firmware storage memory.
[0050]
(Supplementary Note 5) a step of performing a test on a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup to detect a defective area in the memory; ,
Without accessing the specific area of the memory, a firmware program corresponding to the specific area including the detected defective area is selected from a plurality of firmware programs generated corresponding to the specific area. And shipping the system LSI together with the system LSI.
[0051]
(Supplementary Note 6) In Supplementary Note 5,
In the shipping step, a method for shipping a system LSI, wherein the selected firmware program is stored in a firmware storage memory in the system LSI.
[0052]
(Supplementary Note 7) In a compiler program for generating the firmware program in a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup,
Inputting and analyzing the firmware program,
Converting the access code to the defective area in the memory into an access code to the outside of the defective area and converting the code to an object code.
[0053]
(Supplementary Note 8) In Supplementary note 7,
The memory has an installation area where the firmware program is installed, and a work area accessed by the firmware program,
A compiler program, wherein in the conversion step, an access code to the defective area in the work area is converted into an access code to an area other than the defective area in the work area.
[0054]
【The invention's effect】
As described above, according to the present invention, even if a defect exists in the built-in memory, the system LSI device can be repaired, and the yield can be increased.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a system LSI according to an embodiment.
FIG. 2 is a chart showing an example of an address space of the system LSI of FIG. 1;
FIG. 3 is a diagram showing a configuration of a memory 12;
FIG. 4 is a diagram illustrating an example of a firmware program according to the present embodiment.
FIG. 5 is a diagram showing another example of a firmware program according to the present embodiment.
FIG. 6 is a flowchart illustrating a shipment process of a system LSI according to the present embodiment.
FIG. 7 is a flowchart illustrating a procedure of a compiler program according to the present embodiment.
FIG. 8 is a diagram illustrating an example of a system LSI according to a second embodiment;
FIG. 9 is a table showing an example of an address space of the system LSI of FIG. 8;
FIG. 10 is a flowchart illustrating a system LSI shipping process according to the second embodiment;
[Explanation of symbols]
10 system LSI, 12 built-in memory, F0 to F4, FA firmware program, B1 to B4 work area

Claims (5)

In a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup,
The memory has the installation area and a work area accessed by the installed firmware program, and the installed firmware program does not access a defective area in the work area. System LSI. In a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup,
The memory has the installation area and a work area accessed by the installed firmware program,
The system LSI, wherein the installed firmware program is installed in the work area when a defect exists in the installation area. In claim 1 or 2,
Furthermore, it has a firmware storage memory storing the firmware program,
A system LSI, wherein the firmware program is downloaded from the firmware storage memory. Performing a test on a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup to detect a defective area in the memory;
Without accessing the specific area of the memory, a firmware program corresponding to the specific area including the detected defective area is selected from a plurality of firmware programs generated corresponding to the specific area. And shipping the system LSI together with the system LSI. A compiler program for generating the firmware program in a system LSI having a CPU that executes a predetermined firmware program and a memory in which the firmware program is installed at startup,
Inputting and analyzing the firmware program,
Converting the access code to the defective area in the memory into an access code to the outside of the defective area and converting the code to an object code.

Images