TRANSMISSION DEVICE AND METHOD FOR CONTROLLING FIFO CIRCUIT

摘要

PROBLEM TO BE SOLVED: To suppress generation of a signal error due to variations in phase of a writing clock without increasing the size of a memory of a FIFO circuit.SOLUTION: The transmission device includes: a writing pointer controlling unit generating a writing pointer, using a writing clock regenerated from a data signal; a reading clock generating unit generating a reading clock; a reading pointer controlling unit generating a reading pointer, using the reading clock; a memory in which a data signal is written into a bit specified by the writing pointer and a data signal is read from a bit specified by the reading pointer; a detecting unit detecting a usage rate of the memory based on difference between the writing pointer and the reading pointer; and a frequency controlling unit generating a frequency control signal changing the frequency of the reading clock if the usage rate is out of an acceptable range specified in advance.SELECTED DRAWING: Figure 2