| 摘要 |
PROBLEM TO BE SOLVED: To provide A/D converter test system and method for substantially shortening test time by reducing the number of times of comparison required for analog/digital conversion. SOLUTION: This system is provided with an upper limit register 20 and a lower limit register 22 for storing respectively an upper limit value (x+m) and a lower limit value (x-m) from the expected value x and allowable range m of an externally inputted external input analog voltage, an A/D controller 24 for transmitting the upper limit value (x+m) and the lower limit value (x-m) and informing the compared result of the external analog input voltage, an SAR 26 for writing the upper limit value (x+m) and the lower limit value (x-m) therein, a digital/analog converter 28 for converting the upper limit value (x+m) and the lower limit value (x-m) written in the SAR 26 to an analog voltage and a comparator 30 for comparing the analog voltage with the external analog input voltage and informing the A/D controller 24 of the compared result.
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