| 摘要 |
PURPOSE: An analog-to-digital converter is provided to secure a more exact characteristic without dependence on its characteristic by recording or masking an ideal data value in a code data part previously. CONSTITUTION: An analog-to-digital converter(ADC) control register(11) sets an operation mode of an ADC, and a sample and hold circuit(12) stores an analog input signal(AVin). A reference voltage generator(13) generates a reference voltage(AVref), and a comparator(14) compares an output value of the sample and hold circuit with the reference voltage to output a logic low or high signal depending on a comparison result. A successive access circuit(15) stores an output value of the comparator(14) and changes the reference voltage according to the output value of the comparator(14). The circuit(15) outputs a signal for informing completion of an analog-to-digital conversion operation to the control register(11). An output data storing register(16) outputs a digital value, obtained by converting an output value of the circuit(15), through a data bus when a read signal is inputted from the control register(11). A decoder(17) decodes an output data value of the register(16). A code data part(18) records or masks previously coded data so that a data value decoded by the decoder(17) corresponds to an ideal data value. A code data outputting and storing register(19) stores coded data from the code data part(18), and a logic control part(20) controls so as to decode a stored value of the register(16) and selectively decode a stored value of the register(19).
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