International Business Machines Corporation

Guy Richard Currier

Steven Michael Douskey

Paul L Wiltgen

Sharon Denos Vincent

James Scott Harveland

James Maurice Wallin

Paul Allen Ganfield

Leland Leslie Day

John Robert Elliott

Michael Charles Cogswell

An oscillator transmission switching circuit switches between asynchronous oscillator signals with low latency. Preferably, a fast switching circuit triggers a transition from a first oscillator to a second oscillator by entering a bridge input immediately following an edge of the first oscillator, holding in the bridge input until the same edge of the second oscillator is detected, and switching to the second oscillator. Preferably, the bridge input is selectable to accommodate conditions in which the first oscillator signal is stuck at either a logic 0 or a logic 1. A change of oscillators may be triggered by a fault detection circuit or by an external signal.

Oscillator transmission and switching apparatus for a digital data processing system

Methods and apparatus are provided for connecting a manufacturing test interface to a global serial bus, such as an inter integrated circuit (I C) bus. Input/output buffer logic buffers data to be transferred to and from the global serial bus. A slave interface logic connected to the input/output buffer logic receives and sends data to the input/output buffer logic. A slave controller coupled to the input/output buffer logic and the slave interface logic paces data exchange to the input/output buffer logic. Error detection logic is coupled between the input/output buffer and the global serial bus for detecting error conditions.

Method and apparatus for connecting manufacturing test interface to a global serial bus including an I2 c bus

A data processing system, circuit arrangement, program product, and method thereof utilize a multi-path scan interface that is capable of providing multiple scan paths into a plurality of scan ring segments in an integrated circuit device. The multi-path scan interface utilizes one or more multiplexers coupled between scan in and scan out ports and at least one scan ring segment to provide alternate scan paths depending upon select signals supplied to each multiplexer. With such a configuration, a standardized scan interface may developed for interfacing with a wide variety of scan ring segments, and optionally, for multiple purposes. As a result, the amount of custom circuitry necessary to provide access to scan ring segments is significantly reduced.

Data processing system, circuit arrangement and program product

A data processing system, integrated circuit device, program product, and method thereof utilize a service interface to provide external access to a plurality of cores integrated into an integrated circuit device. The service interface, which may be utilized to perform external data transfer through a service access port in connection with a predetermined service operation, is separate from any function interface that is utilized during regular operation of the device. The service interface includes a plurality of core interface units integrated with selected cores on the device and coupled to the service access port through a master interface unit that is configured to request at least one of the core interface units to initiate execution of a predetermined service operation. As such, a multitude of service operations may be initiated in any number of the cores through a common service access port without occupying a large number of I/O pins and without necessitating interruption of the regular operation of the device.

Growing community of inventors

Rochester, MN, United States of America

Guy Richard Currier