| 摘要 |
PROBLEM TO BE SOLVED: To prevent a malfunction without being restricted by the input/output operation frequency.SOLUTION: A data transfer device 100 includes: storage means (FIFO memory 131b) for which data write is performed in synchronization with a first clock and data read is performed in synchronization with a second clock whose frequency is different from the first clock; first comparison means (comparator 137b) that compares a write address and read address for the storage means in synchronization with the second clock; second comparison means (comparator 138b) that compares the write address and read address for the storage means in synchronization with an inverted output of the second clock; notification means that sets a flag for providing a notification of the vacancy state of the storage means according to a result of comparison by the first comparison means and a result of comparison by the second comparison means; and control means that performs data transfer control on the basis of the flag which is set for notification by the notification means.SELECTED DRAWING: Figure 1 |
