International Business Machines Corporation

Daniel Gerard Smyth

Derrick LeRoy Garmire

Kathy Sue Barkey

Harold Edgar Roman

Carl Alfred Bender

A credit-based flow control checking scheme is presented for controlling data communications in a closed loop system comprising a sender, a receiver and a link coupling the sender and receiver. The credit-based scheme includes automatically periodically transmitting a credit query from the receiver to the sender and upon return receipt of a credit acknowledge containing the available credit count maintained by the sender, determining whether credit gain or credit loss has occurred subsequent to initialization of the closed loop system. Along with automatically determining whether credit gain or credit loss has occurred, a method/system is presented for automatically correcting the loss or gain without requiring resetting of the closed loop system.

Credit-based flow control checking and correction method

A self-timed link between two elements in a computer system is initialized. Each element sends an initialization request to the other. If successfully received, the elements exchange signals with oscillation-free segments over multiple clock cycles. If successful, the elements indicate to each other that initialization is complete. Optionally, a link operation parameter can be sent with the initialization complete indication for post-initialization link control.

Method for initializing a self-timed link

System for initializing a self-timed link

Credit-based flow control checking and correction system

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Austin, TX, United States of America

Daniel Gerard Smyth