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Large System Diagnostics With Minimal Hardware

IP.com Disclosure Number: IPCOM000034815D
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 3 page(s) / 16K

Publishing Venue

IBM

Related People

Eckel, JW: AUTHOR [+4]

Abstract

A technique is described whereby a software diagnostic mechanism and procedure enables the testing of large computer systems at all levels, from individual component test, on up to a complete system test. Using software and a minimum of well-placed hardware, the procedure divides the overall diagnostic task into five operational modes. The procedure sectionalizes the hardware into individually identifiable areas, so that microcontrollers can supply test patterns in the determination of malfunctions. One central point of control is used in performing the entire diagnostic operation. The large system diagnostic procedure is designed to provide a central point of control in the testing of large systems.

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Large System Diagnostics With Minimal Hardware

A technique is described whereby a software diagnostic mechanism and procedure enables the testing of large computer systems at all levels, from individual component test, on up to a complete system test. Using software and a minimum of well-placed hardware, the procedure divides the overall diagnostic task into five operational modes. The procedure sectionalizes the hardware into individually identifiable areas, so that microcontrollers can supply test patterns in the determination of malfunctions. One central point of control is used in performing the entire diagnostic operation. The large system diagnostic procedure is designed to provide a central point of control in the testing of large systems.

The central point of control, or central diagnostic controller (CDC), is accomplished through the use of a personal computer, such as the IBM PC/AT. Microcontrollers, such as the Intel 8051, are used at various logic sections of the machine. The diagnostic procedure performs the following functions: - Testing at the individual component level is performed by

using software only.

- Interconnecting cables are checked as are the

individual logic assemblies.

- Selectivity designed into the CDC allows any section of

the system to be tested with any number of combinations

of test patterns and real machine signals.

- Individual circuit cards and boards may be tested in the

machine, or removed and tested on the bench, using a

serial communications link to the CDC.

- The diagnostics supplied with the system are used so that

on-line diagnostics can be performed in debugging

portions of the system. The procedure divides the system hardware into the logical sections that are directly associated with the packaging of the system. Items that are purely mechanical, such as printers or readers, are each considered to be their own logical section and are treated individually. Five diagnostic modes of operation are provided: Mode 1 - Complete system test at full speed.

Mode 2 - Complete system test at a slow diagnostic speed.

Mode 3 - Sub-system test.

Mode 4 - Individual circuit board or card test.

Mode 5 - Individual component test. In the implementation of the diagnostics procedure, each logical section utilizes a microcontroller to receive commands from the CDC over a serial communications link. Requested information is then passed back over the same link. The actual testing of circuits is accomplished by disconnecting the inputs that enter the card or board and then supplying those inputs in the form of test patterns. The test patterns may either be stored in the microcontroller's memory or may be sent, as needed, to the microcontroller by the CDC. The outputs from the circuits are monitored in order to determine whether or not the logic acted properly on the given inputs. The results pass back

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over the serial communications link to the CDC. If a particular test failed, provision is made t...