A method and arrangement for carrying out of continuous data transfer in the case of executing of a - / outputting operations by means of selector - or block multiplex canals of the a - / output unit of a data processing system

摘要

1. A method of executing continuous data transfers in the streaming mode via a selector or block multiplex channel which connects a peripheral unity (PE) to the channel control unit (CHn) of an input/output unit (IOP) within the scope of input/output operations to be carried out in a data processing system, using a channel control unit (CHn) whith a buffer store (BUF A/B) preceded by a receiving register (DINR) for data incoming via the channel, which receiving register temporarily intermediately stores the data which is to be transmitted or which has been transmitted, and with a flow control unit (TK-ST) for the channel-side data transfer, characterized in that - during the introductory phase of a data transfer from the peripheral unit (PE) the execution of the data transfer in the streaming mode is indicated by an additional interface signal (SMC) on a previously unrequired interface line by the channel control unit (CHn), - that the actual execution of the streaming mode is dependent upon the prompt emission or a confirmation message from the peripheral unit (PE) by a predetermined interface signal (e. g. disconnection of RDY), where, when the confirmation message is promptly given, the additional interface signal (SMC) is maintained and the execution of the data traffic in the streaming mode is safeguarded, whereas when the confirmation message is not promptly given the additional interface signal (SMC) is disconnected, - that in the actual execution of the streaming mode, the items of data (DIN) transmitted from the peripheral unit (PE) are transmitted via an additional buffer store (INBUF) which precedes the receiving register (DINR) and which has its own, channel-end input register (INPREG) and - that all the items of data (DIN) transmitted during the streaming mode from the peripheral unit (PE) are also accompanied by a validity strobe (CESTB) which controls the transfer of the received data into the input register (INPREG) and, in association with the flow control unit (TK-ST), controls the transfer to thee receiving register (DINR) via the additional buffer store (INBUF) and from there into the actual buffer store (BUF A/B).