| 摘要 |
<p>PURPOSE:To eliminate the necessity of an RAM for previously saving the content of an address and, as a result, to lighten the burden of software, by providing a switching circuit between a conventional data memory and output controlling circuit and reading out the content of a latched address. CONSTITUTION:In this invention, a switching circuit 9 is provided between a conventional data memory 4 and output controlling circuit 5. The switching circuit 9 is composed of a control signal input terminal 10, upon which control signals of switching the mode between one for outputting the data of the data memory 4 and the other for outputting the address latched in an address latching circuit 2 are impressed, inverter 11 which inverts the control signals, OR gates 121, 123, 125 and 127 for taking the OR of the output of the data memory 14 and control signals, OR gates 122, 124, 126, and 128 for taking the OR of the output of the address latching circuit 2 and output of the inverter 11, namely, the inverted signals of the control signals, and AND circuits 181-184 which respectively take the AND of the outputs of OR gates 121 and 122, 123 and 124, 125 and 126, and 127 and 128.</p> |
