| 摘要 |
PURPOSE:To prevent a picture signal data from an area error due to color blurring or noise components, by providing the titled circuit with an area error detecting circuit to simultaneously detect and discriminate the overflow and under flow of a two-stage adder adding picture signals. CONSTITUTION:Data H, J (J is a negative number) are inputted to a different code input adder 2 to be operated. The status of a carry bit K is transmitted to an area error preventing circuit 5. The added result is inputted to a superposing circuit 3 and a fixed value is added to the result. The status of a carry bit L at the addition in the superposing circuit 3 is also detected to the area error detecting circuit 5. The circuit 5 discriminates whether the final data of the operation are variable, overflowed or underflowed and outputs a control signal M to a maximum/minimum detecting circuit 4. |
