DATA PROCESSING SYSTEM

The present invention provides a data processing system which can increase resolution and which has excellent tracking with respect to the switching of a conversion range and is small in conversion error. The data processing system, which obtains an A/D conversion result after an n (where n: positive integer)-bit extension made to the resolution of an A/D converter, divides the input range of the A/D converter by m (2n m), determines to which divided range the A/D conversion result by the A/D converter belongs with respect to an analog signal to be measured, amplifies an amp offset which defines the range of the determined divided range as a voltage range for the input range of the A/D converter by applying the amp offset to a programmable gain amplifier, converts the amplified signal by the A/D converter, and adds a corresponding digital offset to a result of execution of a lower side bit extension to the conversion result and a division thereof by actually measured gain of the programmable gain amplifier, whereby an A/D conversion result with a bit precision being n-bit extended is obtained.