| 摘要 |
<p>PURPOSE:To shorten the writing time with a simple operation, by preparing plural sockets for package of programmable ROMs containing data lines and control lines respectively in response to the word length of the writing data and then writing all at once the data of a word length into plural ROMs. CONSTITUTION:For instance, the data of word length up to double as much as the bit length per address of a programmable ROM1 is written. In this case, the ROMs are packaged into two sockets 26A and 26B respectively, and the same address is delivered to these two sockets through an address line 23. Then writing control signals 25A, 25B and 25C are delivered while the writing data are delivered all at once to data lines 24A and 24B. Then the writing voltage is delivered simultaneously to both sockets. Thus the writing time is reduced down to half and then a cost reduction is attained.</p> |
