Browse Prior Art Database

Optical Diagnostic Mechanism for Large Scale Integration Logic Systems

IP.com Disclosure Number: IPCOM000089689D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Callahan, RW: AUTHOR [+2]

Abstract

This article describes a light-emitting diode (LED) and fiber-optic mechanism for enabling simultaneous observation of many different binary signals on one or more large-scale integration (LSI) circuit chips or the like without resort to the use of cathode-ray tube oscilloscopes or other expensive test equipment.

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Optical Diagnostic Mechanism for Large Scale Integration Logic Systems

This article describes a light-emitting diode (LED) and fiber-optic mechanism for enabling simultaneous observation of many different binary signals on one or more large-scale integration (LSI) circuit chips or the like without resort to the use of cathode-ray tube oscilloscopes or other expensive test equipment.

While this mechanism is good for monitoring selected signals at any given level of electronic circuit packaging, a typical example is represented in Fig. 1, wherein various LSI circuit chips 10 are located in various module packages 11 which are, in turn, mounted on a printed-circuit card 12. The selected circuit points to be monitored are connected to different LEDs in an LED array 13 mounted on the card 12. The signals to be monitored are binary or "two-level" in nature. If a given signal is at the active level, it turns on its individual LED in the array 13 and, if at the inactive level, does not turn on its LED.

Each LED in the array 13 is optically coupled to a different fiber in a coherent optical fiber bundle 14, which is connected to the array 13 by way of a connector 15. At the external interface 16, the fibers are separated so that the ends thereof provide a two-dimensional array. The human observer 17 views this interface array by means of an opaque template 18 having a two-dimensional array of holes therein. Fig. 2 shows a front view of the template 18.

Each optical fiber...