High speed synchronous data transmission system and its transmission method

摘要

In a high-speed synchronous data transfer system, a receiver functional unit (21) is synchronized with a transmitter functional unit (20) by a common clock. The receiver functional unit (21) includes a first register (26) for holding data from the transmitter functional unit (20) at a predetermined timing in the middle of a machine cycle, a second register (28) for holding the data held in the first register (26) at the end point of the machine cycle, a first state holding unit (27) for holding a specific interface signal, output from the transmitter functional unit (20), and representing data transfer from the transmitter functional unit (20), at the same timing as the first register (26), and for indicating whether effective data is held in the first register means, and a second state holding unit (29) for inhibiting, when effective data is held in the first register (26) but is not permitted to be loaded in the second register (28), a latching operation of the next data of the first register (26) at the end point of the machine cycle.