Abstract: A threshold setting circuit receives a signal coupled to the signal terminal of a comparator, delays then amplifies the signal and couples the delayed-amplified signal through a switch to the threshold signal terminal of the comparator. Prior to the reception of a signal which exceeds the threshold, the threshold level is set at the amplified noise level which is stored in storage means coupled to the threshold signal terminal. When the signal exceeds the amplified noise level, the switch is opened prior to the time that the delayed amplified signal is coupled to the threshold signal terminal and stored with the amplified noise in the storage means. Sometime after the signal ceases to exceed the amplified noise threshold level the switch is closed and the storage means tracks the amplified noise to maintain a current threshold level.

Abstract: A shaft angle encoder interface for quadrature channel incremental shaft angle encoders utilizes a quadrature decoder/counter interface integrated circuit for providing a digital signal output representative of the angle. The digital signal output is provided by a high byte and low byte multiplexer. The integrated circuit includes inhibit logic for inhibiting updating the data when the output is read. A state machine controls latches that receive the high byte and low byte to assemble an output digital angle signal and provides control signals to the integrated circuit so that the inhibit mode is not activated.

Abstract: Built-in test equipment performs time out tests on a plurality of fast lines and a plurality of slow lines with respect to a short time interval and a long time interval respectively. The fast inputs are multiplexed under control of a first sequencing counter and the slow inputs are multiplexed under control of a second sequencing counter. The counter outputs set up logic so as to differentiate the error status with respect to the lines. Additional counters sequence the logic through the operations to be performed on the lines and are utilized to clock the sequencing counters.