US H1,342 HGranted

Effectuating full duplex digital data transfer

AssigneeThe United States of America as represented by the Secretary of the Navy

InventorEric J. Whitesell

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Abstract

A method for the simultaneous bidirectional transfer of digital data at a ry high rate between a host digital data processor and an external device includes the steps of: loading the output data into a data register of the processor; loading an address reference of an external device into an address register of the processor; forming a composite address consisting of the sum of the data register and an address register; and exporting the output data through the address lines from the processor to the external device while simultaneously reading data into the processor from the external device. The method accomplishes rapid data transfer by advantageously transferring data over what would normally be address lines between the processor and the external device. This method is suitable for applications where data is to be transferred from a processor operably coupled to only one external device.

Claims3

Dependent claims

A method for transferring digital data between devices, comprising the steps of:

executing a first instruction in a digital processor, having address and data lines which fetches m-bit output data from a memory into a data register, where "m" is a positive integer;
executing a second instruction in said digital processor which fetches an address reference of an external device from said memory into an address register of said digital processor, said external device having n-bit external data on external data lines, where "n" is a positive integer;
and
executing a third instruction in said digital processor which places said output data and said address reference onto said address lines, and causes said output data from said address lines of said digital processor and said external data from said external data lines to be sampled by a plurality of data latches, and causes transference of said output data to said external device and transference of said external data to said digital processor from said plurality of data latches substantially simultaneously.

1 more element

Dependencies are inferred from the claim text.