| 摘要 |
PURPOSE:To make it possible to write also data prevented from limitation of a write enable signal by selecting the writing of data in a RAM independently of or in accordance with the write enable signal through a selecting means. CONSTITUTION:When an address is inputted to a RAM address selecting circuit A and a write enable signal in a data write enable signal discriminating circuit B is enabled at an initializing time, writing to a data write memory cell C is controlled so as to be executed simultaneously with the input of data without the limitation of the data write enable signal. When the write enable signal is not initialized, a data write enable signal confirming circuit D is controlled through the circuit B and data are written in the cell C in accordance with a write enable signal supplied from the external. Consequently, the data independent of the limitation of the write enable signal can be also written and simple and rapid writing operation can be attained without generating the data enable signal in each data. |
