| 摘要 |
<p>PURPOSE:To change the data of a mask ROM, by performing the inversion of the data of the mask ROM or the selection of change information corresponding to the change information of a PROM. CONSTITUTION:When an address signal 110 to designate the part to be changed of the mask ROM111 is introduced, a change information designating means 121 designates an address to read out the change information stored in the PROM131, and the PROM131 outputs the change information of a corresponding address. An inversion means 114 inverts 141 the data outputted from the mask ROM111, or the selection means 151 selects the change information of the PROM131.</p> |
