| 摘要 |
A method for generating PCM logarithmic values from linear values and storing these values in memory for efficient and rapid data retrieval is shown. This is an off-line method of generating the contents of a programmable read only memory for rapid on-line conversions from linear to logarithmic PCM values by an ISDN system. This method generates either negative or positive PCM values. An initial value and memory address are determined. Next, memory address is incremented and is PCM value decremented. The resulting PCM value is stored at successive locations throughout the memory. Each PCM value comprises a step of a segment. These operations are iterated for each of the segments required for conversion for both positive and negative PCM values.
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