BIT (Built-In Test) circuit of multipath ground/open discrete magnitude input signal

Abstract

The invention provides a BIT (Built-In Test) circuit of a multipath ground / open discrete magnitude input signal, which is mainly used for solving the problems of long test cycle, high measurement cost and poor reliability of test result in prior art. The BIT circuit of a multipath ground / open discrete magnitude input signal comprises at least two paths of serially connected second order filter circuits, a buffer circuit and a drive circuit, wherein one end of the second order filter circuit is a discrete magnitude input end while the other end thereof is a data output end, and the buffer circuit and the drive circuit are further connected with a decoding control circuit which is used for controlling data transmission and instruction decoding. The BIT circuit of a multipath ground / open discrete magnitude input signal only additionally adds two combined relays in hundreds of normal signal processing circuits, so that circuits are simple, practical and reliable, and the testability and the reliability of the circuits are improved greatly.

Description

technical field

[0001] The invention relates to a BIT test circuit for multiple ground / on discrete input signals, which is used for processing the discrete signals. Background technique

[0002] In computer discrete input circuits, there are nearly a hundred independent discrete input channels of the ground / open type, and discrete signal processing circuits generally include input isolation circuits, EMI (electromagnetic compatibility) circuits, level conversion circuits, buffer drive circuits, decoding Control circuit, BIT (self-test) support circuit and other components.

[0003] The number of ground / open discrete independent input channels is large, and the normal signal processing circuit is very complicated. When using the existing test method to test it, the test mechanism itself is relatively complicated, the test cost is high, and the test period is long. And the reliability is poor; therefore, there is an urgent need to provide a well-tested, simple and practical B...

Images