SIGNAL CONVERTING METHOD AND DEVICE, AND IMAGE SIGNAL PROCESSOR

PROBLEM TO BE SOLVED: To minimize a disorder of a signal in a device which writes a nonstandard signal into a memory in units of 1 cycle according to a timing signal in synchronism with a cycle of the nonstandard signal, reads out the written nonstandard signal from the memory according to the timing signal in synchronism with an internal reference signal, and converts it into a standard signal in synchronism with the internal reference signal. SOLUTION: When a cycle of a nonstandard signal is longer than that of an internal reference signal, a start of reading out data corresponding to 1 cycle of a nonstandard signal from a memory is stood by so as to come after an end of writing data corresponding to 1 cycle of the nonstandard signal into the memory, and then a readout follows a write. When a cycle of the nonstandard signal is shorter than that of an internal synchronous signal, a readout is conducted independently of a write. Further, when the write of the nonstandard signal into the memory passes the readout of the nonstandard signal from the memory, a cycle when a passing occurs is skipped.