Bi-directional asynchronous transfer scheme using a single handshake

摘要

A bi-directional transfer device for transferring packets of data across an asynchronos boundary separating a first time domain includes control logic which utilizes a single handshake signal to both request that the first time domain receive a packet of data from the second time domain, and, acknowledge receipt of an immediately previous packet of data by the second time domain from the first time domain. The device is bi-directional in that for each packet of data sent from one time domain, a corresponding packet of data should then be received from the other time domain. If one time domain has several more packets of data to send than the other time domain, the time domain with fewer packets of data sends invalid packets of data and asserts a signal indicating that the packets of data are invalid. The device is expandable such that two or more packets of data can be simultaneously exchanged across the asynchronous boundary. The device can be used in a method for bi-directionally transferring packets of data across an asynchronous boundary where a single handshake signal is used to request a data packet and acknowledge receipt of an immediately previous data packet.