Abstract: The embedded micro-controller unit includes a serial interface according to the present invention. A program control device connects the embedded micro-controller unit. The serial interface will send a request signal to a micro-processor while renewing program codes. The micro-processor will transfer the power of controlling program memory to the serial interface and then go into idle state or halt state after receiving the request signal. The program control device may directly write new program codes into the program memory through the serial interface.

Abstract: An analog-to-digital converter receives slow-varying analog voltages from a sensing device and converts the slow-varying analog voltages to digital signals. The sensing device generates a slow-varying analog voltage directly proportional to absolute temperature. The analog-to-digital converter includes a second counter which receives the pulse train from the second voltage controlled oscillator that counts the number of pulses which informs the first counter whenever the count value thereof reaches a fixed number and resets the count value thereof to zero. As the first counter is being informed by the second counter, its count value is read and then reset to zero. The read count represents a digital signal corresponding to the slow-varying analog voltages input.