US Patent 7209066 Circuit and method for extending microcontroller analog input capability

A circuit and method extends the analog input capability of a microcontroller by including an autonomous sequence control circuit that supplies input signal setting data and implements delay functions independent of the microcontroller central processing unit (CPU). The sequence controller supplies input signal selection commands to an input multiplexer, and analog signal processing commands to one or more analog signal processing circuits. After a predetermined settling time, the sequence control circuit then initiates an analog-to-digital converter (ADC) to convert the select analog signal to digital data. The circuit and method extend the number of available external address bits and the maximum settling time of the ADC.