| 摘要 |
<p>PURPOSE:To miniaturize a substrate and to reduce circuit parts by composing the title device of a PROM having 2<n>-type capacity, an address register having a PROM structure, and a comparing circuit to output a chip selecting signal for the PROM. CONSTITUTION:The device has a 2<n>-type capacity PROM 7 connected to (n) (n: positive integers)-bit address input terminals A0-A13 and a PROM structural address register 5 connected to the (n)-bit address input terminals A0-A13 and (m) (m: positive integers)-bit address input terminals A14 and A15 added besides A0-A13. Further, the device is composed of a comparing circuit 6 to compare address values from the (m)-bit additional address input terminals A14 and A15 with address values obtained from the address register 5 and to output the chip selecting signal for the PROM 7. Moreover, this comparing circuit 6 can be provided in the external part of the PROM 7. Thus, a circuit substrate can be miniaturized, and the number of the parts can be reduced.</p> |
