Information processing unit with failure information management function and failure information management method four

When a PWB is returned to the unit producing factory, the history of the past failure information can be grasped with reliability. An information processing unit with a failure information management function under a host unit to send/receive information to/from the host unit and having a plurality of PWBs, includes: the PWBs each provided with rewritable ROM; wherein at least one of the PWBs has a CPU for controlling sending/receiving of information to/from the host unit and input/output of information of the rewritable ROM; the rewritable ROM stores the identification code and the failure information of the PWB.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described hereinbelow in detail. Referring to FIG. 1 , in the embodiment of the present invention, an information processing unit 2 with a failure information management function includes a plurality of PWBs 11 a, 11 b, 11 c and 11 d. A flash ROM (which stands for Flash Read Only Memory, is also called a flash memory, and means a rewritable ROM capable of electrically erasing stored data) is mounted onto each of all the PWBs. Here, flash ROMs 14 a, 14 b, 14 c and 14 d are respectively mounted onto the PWBs 11 a, 11 b, 11 c and 11 d. CPUs 12 a and 12 c are respectively mounted onto the PWBs 11 a and 11 c. No CPU is mounted onto PWBs 13 b and 13 d. There are mixed the PWBs mounting the CPU and the PWBs not mounting the CPU. At least one PWB mounting the CPU must be in the information processing unit 2 . The flash ROMs 14 b and 14 d each including an identification code and producing date information are mounted not only onto the PWBs with the CPU but also onto the PWBs 13 b and 13 d not with the CPU. Regardless of whether the CPU is present or not, the identification codes are added to all the PWBs and the producing dates are written thereinto. Referring to FIG. 2 , the PWB 11 a having the CPU has the CPU 12 a for controlling the operation of the PWB 11 a and the PWB 11 b not having the flash ROM, an external I/O 22 connected to a host unit 40 for reporting a failure, an RAM 23 for holding a program being executed, the flash ROM 14 a for adding an identification code and storing a producing date, and an internal I/O 25 for controlling other PWB. The flash ROM 14 b is mounted onto the other PWB. The information processing unit 2 is under the host unit 40 (for example, corresponding to a host computer) and sends/receives information to/from the host unit. The information processing unit 2 corresponds to, for example, a magnetic disk apparatus, a magnetic tape unit, an optical disk drive, a printer, other peripheral devices, and a controller for controlling the peripheral devices. Referring to FIG. 3 , the information processing unit of the present invention uses a 16 Mbyte flash ROM having an 8-Bit width and 32 banks (the flash ROM is typically divided into a plurality of banks and permits erasing for each of the banks). There are four kinds of banks of a boot bank 31 for storing a boot program used when the CPU is booted up, a program bank 32 for storing a program for having control over the operation of the CPU, a parameter bank 33 for storing control parameters indicating the setting information of the unit, and a management bank 34 for storing failure information. One flash ROM has at least four regions having a single kind of bank. The operation of the embodiment of the present invention will be described hereinbelow. The boot bank 31 stores a boot program used when the CPU 12 a is booted up. Only the boot program is written into the boot bank 31 before the flash ROM is mounted onto the PWB ( 11 a ), and then, the flash ROM is mounted onto the PWB. Nothing is not written in this bank after the mounting. The boot program copies a program in the program bank 32 from the flash ROM 14 a to the RAM 23 for execution when the information processing unit 2 is booted up. An error detection code is checked during the copying. When there is no abnormality, normal operation can be ensured. Without using the program stored in the program bank, the downloading operation from the host unit 40 is executed to obtain another program. This can execute a latest revision program in the field. When both the host unit 40 and the information processing unit 2 are booted up, the contents of the program bank 32 are erased. A program transferred from the host unit 40 by downloading is written thereinto. The program transferred by downloading upon the next booting-up is copied from the flash ROM 14 a to the RAM 23 for execution. The control parameters indicating the setting information of the unit (such as IP address, physical address, and the next information used when the power is turned off) and used for controlling the unit are stored in the parameter bank 33 . To prevent the parameters from being lost during rewriting due to a failure, two banks are allocated into the parameter bank 33 so as to be doubled. The doubling is performed in a manner such that erasing and writing are done for each of the banks to confirm after the completion of updating of one of the banks that the parameter is written normally, and then, the other bank is updated. The parameter bank 33 can be rewritten by an instruction from the host unit 40 to meet the user demand after shipping. FIG. 4 shows one example of a block diagram of a table stored in the management bank 34 . A method for using the management bank 34 is different from that of the above-mentioned bank. The management bank 34 is mounted in an erased state. After the completion of mounting, the power is turned on, only one writing processing is performed by an instruction from dedicated producing equipment, not shown, connected to the external I/O 22 . Then, a PWB identification code (corresponding to a serial number) indicating what PWB is used, a PWB producing date, names of parts mounted onto the PWB, and a revision thereof for each of the parts are written for shipping. In particular, chips for storing the control program, circuit, and hard logic manage the revisions. These are useful as reference information for analyzing a failure of the PWB. The parts are mounted mechanically. It is difficult to write the different contents into a plurality of ROMs at the same time before mounting. Therefore, these codes are not written into the flash ROMs before mounting. The writing is in principle performed only in the factory after the parts are mounted onto the PWB. The different contents are written into each of the ROMs, because writing in a state that the parts are mounted is at low cost. Into the management bank 34 , the part name of the consumable part (e.g., a battery 1 ) and a replacement date as the replacement time thereof are written in order that when a predetermined time elapses from the replacement time the host unit detects it to notify it to the user. The item may be written not only in the factory before shipping but also in the field after shipping so that the part can be replaced in the field. Further, into the management bank 34 , the failure spot, the failure contents, the failure date, and the like are written when specified in the PWB 11 a. The failure spot and the failure contents can be easily specified by abnormal detection means using a known technique such as parity check or CRC check. The failure contents include, for example, reporting of input data abnormality, output data abnormality, and abnormal termination during writing. The failure contents can be added sequentially to the item in the field after shipping. The item serves as a log of the past failure information. Generally, when the unit of the present invention detects a failure is caused in the PWB 11 a on which the CPU 12 a is mounted, control of the CPU 12 a allows accumulated failure information with the identification code of the flash ROM 14 a added thereto to be transferred as a log through the external I/O 22 to the host unit 40 . When the abnormal detection means described later detects that another PWB 13 b under control of the CPU 12 a is failed, the failure information with the identification code of the flash ROM 14 b added thereto is transferred through an internal I/O 25 and the external I/O 22 to the host unit 40 . These logs are transferred as the logs including the past failure information each time a failure is caused. The contents of the log include the failure spot, the failure contents, the failure causes, and the failure date. The failure spot, the failure contents, and the failure cause can be easily specified by the abnormal detection means, not shown, present in the information processing unit using a known technique such as parity check or CRC check. The failure contents include reporting of input data abnormality, output data abnormality, and abnormal termination during writing. When a failure does not occur and a predetermined period elapses from the PWB producing date of the PWBs 11 a and 13 b, it is judged that the PWBs 11 a and 13 b have run down or are consumed to replace the PWBs. It is possible to avoid a failure caused by continued use of the consumed PWB. Since the host unit 40 is connected to a management center by a communication line, logs are sent from the host unit 40 to the management center. The logs are managed together in the management center. A PWB is replaced at the site (or in the factory) The PWB removed by replacement is sent to the repair center. The log into which the detailed failure contents managed together in the management center are written and the identification code of the replaced PWB are managed in a unified way. In this way, there pair efficiency of the failed PWB can be increased to enhance the maintainability of the unit. In this case, when there is no log sent to the management center, the failure information described above is stored in the PWB itself. This is read in the repair center to increase the repair efficiency of the failed PWB. The CPU in the PWB monitors the producing date and the present time, and then, reports the replacement time of a battery as the consumable part needed to be replaced periodically. The unit itself can manage the PWB without troubling the unit manager, thereby enhancing the maintainability. Referring to FIG. 5 , one example of a method for managing a consumable part will be described. When the information processing unit 2 with a failure information management function is booted up (step 101 ), the CPU 12 a reads a PWB identification code and the last replacement date of a consumable part (a PWB producing date when the consumable part has not been replaced) from the management bank 34 of the flash ROM 14 a (step 102 ) so as to calculate an elapsed time A from the last part replacement date to the present date (step 103 ). On the other hand, a replacement interval B determined for each of the consumable parts is read from a region, not shown, of the management bank 34 (step 104 ) so as to judge whether A is smaller than B (step 105 ). When A is smaller than B, the consumable part does not have to be replaced. The routine is terminated to move to the original operation of the unit. When A is not smaller than B, the PWB identification code and the part name are notified to the host unit 40 so as to be displayed by display means, not shown (step 106 ). The part is replaced manually (step 107 ). When the replacement is completed (step 108 ), the present date is written into the replacement date column in the management bank 34 to update the replacement date column (step 109 ). The above-mentioned processing is done for all the consumable parts. The CPU 12 a reads information from the management bank 34 of the flash ROM 14 b to perform the same processing to another PWB 13 b thereunder. There is described the present invention when the flash ROMs are mounted onto all the PWBs. It is also possible to consider a structure such that the flash ROMs are respectively mounted onto some PWBs, and the failure information management of the present invention is performed to only the PWBs each mounting the flash ROM. In this case, needless to say, the PWBs each mounting the flash ROM can provide the same operation and effect as in the present invention. In a first effect of the present invention, in the case that the above-mentioned maintenance center manages the history for each of PWBs, the history of failure information can be grasped when the PWB is returned to the unit producing factory. Even if there may be a case that some users use the unit without being connected to the maintenance center through a line or that the line cannot be connected temporarily, the PWB itself is sure to hold the failure information so as to easily find what PWB is used. In a second effect, when a PWB includes consumable parts having a limited life, the maintenance equality will not be varied. When the PWB includes the consumable parts, the host unit can recognize that these consumable parts needs repairing. Even when the maintenance manager does not manages the PWB including a plurality of parts, the replacement time can be grasped sufficiently. Further, the identification code, the producing date, and other failure information are written into each PWB itself so that a processor can read them. The failure information is used during repairing of a PWB, thereby increasing the failure relapse. The number of unrepairable products is reduced to enhance the reusability of the PWB. While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is, therefore, contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.