International Business Machines Corporation

Jayesh M Patel

Maulin Ishwarbhai Patel

John C Kennel

A method and apparatus for non-interrupt-driven handshake with acknowledgment are provided. A first software resource in a data processing system communicates a data value to a second software resource by writing the data value to a first register field, where it may be read by the second software resource. On writing the data, the first resource sets a write signal in a second register field. If the second software resource attempts to read the data value before it is written by the first resource, a reset value in the second field informs the second resource that any data in the first field is invalid. The second resource then sets a first predetermined value in a third field which informs the first resource that the second has attempted a read. If the data is valid when the second resource attempts the read, the data is retrieved, and the second resource echos the value in a fourth field. The second resource also sets a second predetermined data value in the third field which informs the first resource that the data has been read. The first resource then reads the value echoed in the fourth field to determine that the read by the second resource was error free.

Method and apparatus for state-independent non-interrupt-driven handshake with positive acknowledgement

Provided is an apparatus and method for remote retrieval of an integrated-circuit state according to the present invention uses a remote input/output (&ldquo;RIO&rdquo;) processor with a test circuit interface, which in the preferred embodiment is the TAP,. The test circuit interface is for electrically-coupling to an integrated circuit having a test circuit with at least one register for storing a state-information with respect to the integrated circuit. The RIO processor executes a program that instructs the RIO processor to retrieve the state-information in response to a request command. The retrieved state information is transmitted for analysis at a location remote from the computer system using a data-and-instruction communication device. A method of the present invention has a step of issuing a request command for state-information of the integrated circuit having, retrieving the state-information of the integrated circuit in response to the command request; and transmitting the state-information to a location remote from the integrated circuit such that the state-information is available for analysis by a service technician.

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Austin, TX, United States of America

Jayesh M Patel