| 摘要 |
PURPOSE:To prevent malfunction, by keeping a gain coefficient to a positive value when the gain coefficient controlled with a control means based on the detection of the overflow is 0 or negative. CONSTITUTION:While a signal indicating an overflow from a carry processing circuit 4 is given to a gain control circuir 13, if a gain coefficient (k) is changed to a smaller value with the change in the cut-off frequency fc, a data (k') applied from an adder 14 is positive in a gain coefficient control circuit 2, that is, if the code bit being the most significant bit is zero, AND gates 61-67 are opened and the input data (k') is outputted as a coefficient (k''). If the data (k') is 0 or negative, the output (k'') of the gain coefficient control circuit 2 is set to ''2<-8>''. |
