DE2717375A1 - Microprogrammed data processor software and hardware fault location - using lamp array normally indicating operating mode and comparing instruction with stored list - Google Patents

Abstract

A circuit locates software and hardware errors in registers of processor controlled microprogrammed devices for data processing. It enables error location without need of additional circuits or monitoring of each register location. When an error occurs an eight Lamp array is activated which identifies the addressed instruction of the microprogram in operation. Determination of software or hardware error is achieved by comparison of the instruction with a stored list. A special indication program is initiated when an error occurs and is used to drive a lamp array normally used for operating mode display. A single error lamp is also illuminated.

Description

The invention relates to a circuit arrangement for locating

of program or hardware errors in memories of processor-controlled, microprogrammed data processing devices and a method for carrying out the location.

In the case of data processing devices, which today are often done by microprocessors can be controlled, errors in operation can also be caused by errors on Lret'r, that either the saved program (e.g. user program) is incorrect or that the memory has errors (e.g.

because the cells of an integrated memory chip are not working properly are).

In all of these cases, the processing is carried out by the device either erroneous results or an error lamp indicates the occurrence of errors without the operator being able to recognize whether the fault was caused by the machine or caused by an operator error. The operator must therefore by repeating the machining process, check whether no There was an operator error. Is established in this way that a program or If there is a hardware failure, it is necessary to remove the memory chips from the machine - For example, booking machine, billing machine, text processing device 0. a. - to be taken and in a special test device step by step from the first check to the last memory space.

The invention is based on the object in devices of the above Kind of a way of locating program or hardware errors in the memory to accomplish, without the need for additional equipment o, ler Every space would need to be checked.

According to the invention, this object is achieved by the characterizing features of the claim 1. specified features resolved.

The advantages achieved with the invention tinker in particular in that a possibility has been created with simple means, immediately when it occurs of an error to determine whether it was an operating error and - if it is a question of a program or hardware error - that without much search effort the location in the memory that is faulty or one is determined immediately Contains incorrect command. All that needs to be done is the one displayed on the lamp field Compare the command with a program list.

In an advantageous embodiment according to claim 4, a lamp field, as is provided for other purposes in many data processing devices - e.g. B. for displaying one of several programs that is currently in use - also used to display the memory content for fault location. In In this case, there is even no need for a separate lamp field.

An embodiment of the invention is shown in the drawings and is explained in more detail below. They show: FIG. 1 a block diagram of a data processing device and FIG. 2 shows a flow chart.

FIG. 1 shows the functional blocks essential for explaining the invention a data processing device, for example a billing machine, shown. An input keyboard 1, a printing unit 2, a controller 3 and a memory 4 are available via a data bus 5, an address bus o and a control bus 7 with each other in litender Connection control 3 and memory 4 are part of a microprocessor (or Microcomputer), the memory from a ROM or PROM, a RAM or from can exist both.

All other assemblies known to be contained in a microprocessor, such as B. registers, accumulators, ALU, etc., are not for the sake of clarity; i: shown individually but as part of the control 3 and memory blocks 4 to look at. A lamp field 8, which should be provided with 8 lamps, is also controlled by the controller 3, the values to be displayed in a lamp register 9 can be provided in the controller. Furthermore is a.

Error lamp 10 is provided when a program or hardware error occurs is also uncontrolled by the controller 3. These can be those known in Devices usual error lamp to indicate an operating error act, the to display an operating error lights up constantly while it indicates a program or Hardware error flashes.

However, separate lamps can of course also be used will. A command counter 11 contained in the controller 7 is used in a known manner Way of sequential addressing of microinstruction sequences ifl memory 4, the can be read from the memory during a program run.

With the aid of the flow chart of FIG. 2, the functionality if a program or hardware error occurs. A saved Command list contains all commands permitted for the various microprogram sequences, which in the present example consist of 8 bits each. Every single command "A" of a running microprogram is with the commands stored as a command list "B" compared. A positive comparison result causes the processing the program is continued without interruption. A negative comparison result but has the consequence that a special error display program is put into action will. This first causes the activation of the error lamp 10, thus the operator Person becomes attentive. In the further process, the from the command counter becomes the point in time of the error addressed memory content (= command consisting of 8 bits) into the Inscribed lamp register 9 and displayed in the lamp field 8.

The 8 lamps in the lamp field thus show the current code combination of the addressed storage space.

The operator is now able to use a printed out Command list or a printed program to determine at which point the error is located.

To scroll backwards or forwards in the memory are a Key "V" and a key "R" arranged in the keyboard. Such a forward or Scrolling backwards may be required to either find the incorrect code combination to be able to localize them with the help of the correct code combinations surrounding them or in cases where the error occurred a few program steps earlier, but has not been recognized because of the incorrect code combination yet was a permissible command that only resulted in noticeable errors has led.

If the "V" key is pressed, the address is vo; l B-error counter 11 in the controller 3 is increased to the value t1, while when the ".t" key is pressed the address is decreased by the value 1. Now that of the changed Address-addressed command in memory 4 is written into lamp register 9 and displayed as a code combination by the 8 lamps in the lamp field.

The special display program now asks the "V" and R keys to continue constantly from whether an actuation has taken place. Has the fault been located and another It is no longer necessary to display the commands in the lamp field 8, so a button "C" is actuated, which causes the error lamp 10 to go out and a return to the program has the consequence.

Instead of the list on which the example is based permissible commands that are stored in the device as a comparison list Of course, the complete or individual program sequences are also available as a comparison list as well as other features of the programs suitable for error checking. Likewise, the idea of the present invention also includes solutions in which the display of the commands on the lamp field only after one or more actuations a button is triggered, so where z. B. initially after the error lamp lights up Buttons must be pressed. It is also conceivable that the command addresses before the commands are displayed - also possibly key-controlled - by the Lamps are displayed. If the number of address or command bits is larger than the number of lamps provided, an address or of a command in the lamp field can of course also be carried out in several stages.

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Claims (7)

Circuit arrangement for locating program or hardware errors and method for their implementation Patent claims: Circuit arrangement for locating of program or hardware errors in memories of processor-controlled, micro-programmed Data processing devices, drawn by a lamp field, which at Occurrence of an error can be activated in such a way that the addressed command of the current Microprogram can be displayed by the lamps. 2. Circuit arrangement according to claim 1, characterized in that g e k e n n z e i c h n e t that a program ccor llardwarefehler by comparing each instruction of the running microprogram is determined with a stored command list. 3. Circuit arrangement according to claim ?, d a ct u c Y g e k e n n notices that when it occurs. a special display program is put into action. 4. Circuit arrangement according to claim 3, d a d u r c h g e k e n n z e i c h n e t that a Lz..penfeld arranged on the data processing device, which is normally used to display the respective working mode, for fault location is used. 5. Circuit arrangement according to claim 3 or 4, characterized in that that the lamp field has 8 lamps. 6. Circuit arrangement according to claim 3, 4 or 5, dad u r c h g e k e r n z e i c h n e, that an additional lamp is provided that occurs when an error is activated. 7. Procedure for locating program or hardware errors in memories processor-controlled, micro-programmed devices for data processing with a Circuit arrangement according to one or more of Claims 1 to 6, g e k e n n z e i c h n 2 t u r c h the following process steps: a) Compare each one Instruction of the running microprogram with a stored instruction list; b) At If a negative result of the comparison occurs: Write the from the command address addressed memory content in a lamp register and display on the lamp field; c) If necessary. triggered by pressing the "V" (forward) or "R" (backward) key Change of command address by +1 or -1; d) Registered mail of the modified Command address of the addressed security contents in the lamp register and display the lamp field; e) If necessary. Repeat steps c and d.