| 摘要 |
PROBLEM TO BE SOLVED: To improve the use efficiency of the memory of a lookup table in which the range of a value to be converted is dynamically changed, and the wide value to be converted range is always used in an unnecessary way. SOLUTION: Two lookup tables 2 and 3 are serially connected in a hierarchical structure. The upper 16 bit of data to be converted 1 are connected with the address bus of the memory of the master lookup table 2, a flag part 22 of a flag for judging the data to be converted of a conversion data/slave table is provided at the 1 bit of the data, and a data part 21 in which the data to be converted of the conversion data/slave table are stored is provided at the residual 8 hit. The lower 8 bit of the data to be converted and the 8 bit of a data bus 41 of the master lookup table 2 are connected with the address bus of the memory of the slave lookup table 3, and conversion data are stored in a data part 31. When a flag = 0, the data of the master lookup table 2 are selected by a selector 6, and when a flag = 1, the data of the slave lookup table 3 are selected. |
