Abstract: A circuit board with a processing unit and a delay line with a controllable number of delay elements fabricated thereon includes apparatus for testing and calibrating the delay line elements. In the test mode, a calibrated pulse is delayed by the delay line while determining the logic state of pulse at two times, the interval between the two times being the same as the pulse width. By adding delay elements, the period of the calibrated pulse as a function of number of delay elements can determine the delay of each delay element. In the calibration mode, the delay line is configured as a ring oscillator and the frequency of the ring oscillator as a function of number of delay elements provides the time delay for the individual elements.

Abstract: A pulse width modulation module provides a first pulse width modulation signal and a second pulse width modulation signal, the two pulse width modulation signals having the same period, but different duty cycles. Each pulse width modulation module can be programmed to be reset by an external signal and can provide a programmable-selectable reset signal. The possible reset signals provided by the pulse width modulation module can be a signal externally applied to the pulse width modulation module, the reset signal for the first pulse signal modulation signal, and the set signal for the second pulse width modulation signal. In this manner, a pulse width modulation module can act as master or as slave modules, the pulse width modulation signal of the slave module having a selected relationship with the pulse width modulation signals of the master module.

Abstract: In a digital pulse width modulation generator unit, a phase register is coupled to the clocked counter providing the generator unit time base. In response to a control signal, the contents of the phase register over-write the present counter, thereby changing the phase of pulse width modulated generator output signal. When a plurality of pulse width modulated generator units, the phases of the units can be controlled relative to a reference generator. The contents of the phase register can be altered by hardware or by software.

Abstract: To improve the performance of a pulse width modulator, a delay line having number of delay elements receives a pulse signal from the final clock cycle prior to the generation of the trailing edge of the pulse width modulator signal. Each delay element delays the pulse signal a fraction of the system clock cycle. By controlling the number of delay elements prior to the application of the pulse to the trailing edge-generating component, the trailing edge can be adjusted by increments of the clock cycle determined by the number of delay elements. Because parameters of delay elements can vary, a technique for the calibration of the delay line circuit is disclosed.

Abstract: A digital system is provided with an Analog to Digital converter (ADC) that has a configuration that allows a programmable number of Auto conversions to occur on two separate and independent, but cascadeable, sequencers (or state machines). For each conversion state, the sequencer/s can be programmed to arbitrarily select any one of a set of muxed analog input channels. In addition, each conversion state has a unique result register in which the converted value is placed at completion of conversion. This ADC control system gives the capability to set up various forms of input signal sampling strategies. For example, one such strategy samples and converts the same channel multiple times allowing an over-sampling algorithm to be easily performed. By over sampling, increased resolution over traditional single sampled conversion systems can be obtained by suitable processing of the over-sampled results.