| 摘要 |
PURPOSE:To keep the frequency stable for a long period by storing a frequency error coefficient of a crystal oscillator in a nonvolatile memory. CONSTITUTION:A frequency error coefficient alpha of a crystal oscillator 1 is stored in a RAM 9 to obtain a 1st local frequency control coefficient (m) newly and a reception frequency is accurately corrected by controlling a 1st local frequency 2. Moreover, the storage number of the RAM 9 and the storage number of a nonvolatile memory 10 are compared in a controller 8 and if there is a difference over a prescribed value, the storage number in the RAM 9 is transferred to the nonvolatile memory 10. On the other hand, if the storage number of the RAM 9 is missing, the storage number of the nonvolatile memory 10 is transferred again in the RAM 9 to apply the frequency control. Thus, the frequency is kept accurately for a long period. |
