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Semiconductor circuit element device with arrangement for testing the device and method of test

  • US 5,565,766 A
  • Filed: 09/28/1992
  • Issued: 10/15/1996
  • Est. Priority Date: 09/30/1991
  • Status: Expired due to Term
First Claim
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1. A semiconductor circuit device having an arrangement for testing said semiconductor circuit device when mounted on a printed circuit board, said semiconductor circuit device comprising:

  • a plurality of connection pins, each of said connection pins to be connected to conductor connection portions of a printed circuit board,a system circuit,internal lines to be connected to said system circuit and to said connection pins,a plurality of first logic circuits provided in correspondence with internal line groups which are formed by grouping said internal lines into a plurality of groups, a plurality of internal lines belonging to a group in question constituting the input lines of said plurality of first logic circuits, for outputting an active output signal when all of the inputs represent active signals and outputting an inactive output signal when at least one of the inputs represents an inactive signal;

    a second logic circuit constituted by one or more stages of circuit structures, for receiving the outputs of said first logic circuits and sending out an output signal so that the output signal when all of said inputs are inactive output signals is different from the output signal when at least one of said inputs is an active output signal;

    wherein said arrangement for testing said semiconductor circuit device performs a group selection process for selecting one group as the group to be tested from the groups of internal lines;

    inactive signal supply means for supplying an inactive signal through said conductor connecting portions of a printed circuit board to at least one internal line in the lines of the groups which are not selected in said group selection process;

    active signal supply responsive output signal checking means for supplying active signals through said conductor connecting portions of a printed circuit board to the internal lines of the group selected in said group selection process and checking the signal output from the semiconductor circuit element in response to the supply of the active signals, andinactive signal supply responsive output signal checking means for selecting internal lines successively from the internal lines of the group selected in said group selection process, supplying inactive signals through said conductor connection portions of a printed circuit board to the selected internal lines, supplying active signals through said conductor connecting portions of a printed circuit board to the remaining internal lines, and checking the signal output from the semiconductor circuit element in response to the supply of the inactive and active signals.

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