Window detector

Abstract: An image generator (38) in a workstation draws its image data from a pair of frame buffers (32 and 34). The selection between the frame buffers is made by a multiplexer circuit (42) that can switch between frame buffers (32 and 34) on a pixel-by-pixel basis, i.e., different frame buffers can be used during different parts of the same scan frame of a monitor (18) in the image generator (38). A selection-signal source (46), which provides the selection signals for the multiplexer circuit (42), includes a window detector (56), which compares the outputs of counters (72 and 74) that represent the monitor scan position with the outputs of registers (62, 64, 66, and 68) that represent the boundaries of windows used by respective applications that the workstation is running. The source (46) thereby identifies the windows in which the pixel currently being displayed is located, and it employs a priority circuit (76) to identify the one such window having the highest priority. Each software application deposits in a buffer register (70) the identity of the frame buffer (32 or 34) from which the data for its display should currently be drawn, and a priority circuit generates a BUFSEL signal to identify the buffer designated by the application associated with the highest-priority window. It uses BUFSEL to control the multiplexer circuit (42). In this way, all applications do not have to switch between buffers at the same time, so the complexity and lack of flexibility imposed by synchronizing between applications is avoided.

Abstract: The apparatus for metering the state of charge of a battery has a battery current sensor providing a voltage signal dependent on a current flowing into or out of the battery, an integrator for integrating the voltage signal, a window detector circuit providing an output signal each time an output of the integrator reaches an upper or lower threshold voltage level, a digital processing device utilizing the output signals of the window detector circuit to construct a digital battery charge state model, and a switch arrangement for reversing connection of the battery current sensor to the integrator periodically so as to cancel effect of any voltage offset in the output of the integrator.

Abstract: Detection of the existence, magnitude, and frequency of occurrence of a plurality of ESD events is achieved by using an envelope detector to process signals generated by ESD events and received by an antenna The ESD event detector includes an antenna for producing a signal waveform in response to electromagnetic fields incident thereupon, a demodulator coupled to the antenna for generating an envelope waveform that is related to the envelope of the signal waveform, a threshold window discriminator coupled to the demodulator for generating an indication signal if the envelope detected by the demodulator has a magnitude between a first and a second threshold, and a counter coupled to the threshold window discriminator for counting the number of indication signals received from the threshold window detector

Abstract: A cross-correlation fire sensor circuit includes detectors (12, 14) responsive to heat and light radiation, respectively Electrical signals (f1, f2) from the detectors are processed in two distinct channels through low pass filters (20, 22) and samplers (24, 26) The sampled signals from the two channels are multiplied together and the products are summed over a selected interval to provide a correlation function (PHI12) This function is compared with an adjustable threshold to provide an indication of fire sensing The circuit is also included as an adjunct to an existing system to provide improved sensitivity for fire sensing in the presence of noise and enhanced discrimination against false alarms A ratio window detector circuit is disclosed as an alternative cross-correlator for detected radiation