Patent ID: 8614636

Claim:
A data processing system comprising: a microcomputer; and an amplifier circuit, wherein the microcomputer comprises an AD converter circuit, a DA converter circuit, and a control circuit, wherein the control circuit is arranged to control calibration processing, wherein, in execution of said calibration processing under the direction of said control circuit, a gain (G) of said amplifier circuit is calculated, wherein a first voltage (x 1 ) is applied from the DA converter circuit to the AD converter circuit and the AD converter circuit outputs a first AD conversion signal (y 1 ), a second voltage (x 2 ) is applied from the DA converter circuit to the AD converter circuit and the AD converter circuit outputs a second AD conversion signal (y 2 ), the first voltage (x 1 ) is applied from the DA converter circuit to the AD converter circuit through the amplifier circuit and the AD converter circuit outputs a third AD conversion signal (y 3 ), the second voltage (x 2 ) is applied from the DA converter circuit to the AD converter circuit through the amplifier circuit and the AD converter circuit outputs a fourth AD conversion signal (y 4 ), wherein the gain (G) of the amplifier circuit is calculated as G=(y 4 −y 3 )/(y 2 −y 1 ), wherein an offset (O) of the amplifier circuit is calculated as O=y 2 −y 4 /G=y 1 −y 3 /G, wherein AD conversion data (Z) is obtained through the amplifier circuit, and wherein error calibrated data (z) is calculated as z=Z/G−O.