| 摘要 |
<p>PURPOSE:To decrease the memory capacity needed for a table by storing some bits in a memory and having comparison between the boundary input data with which other bit values are changed and the actual input data to obtain said other bits. CONSTITUTION:The highest rank bit B9 is set at 0 with 0<=x<=a and at 1 with x>a in terms of the value of input data (x). In this case, the (a) serves as the boundary input data of the bit B9 and is set a part of the comparison input of a comparator 1. The actual input data is supplied to the other side of the comparison input for comparison of both input data. Thus the output of the bit B9 is obtained from the comparison output (c) of the comparator 1. While the addresses of a ROM2 corresponding to the input data store lower rank 8 bits B1-B8 of the table data and the lower rank 8 bits B1-B8 of the output data are obtained in accordance with the input data. Thus the output data of 9 bits including said unit B9. In such a constitution, the output can be obtained just by a single n-bit comparator for such a bit whose value is switched only once. Thus the memory capacity is decreased.</p> |
