International Business Machines Corporation

Other

Motorola Corporation

Charles G Wright

Harrell Hoffman

Frank Eliot Levine

Charles P Roth

William M Johnson

Edward Hugh Welbon

Donald E Waldecker

Harry Dwyer

Jose M Alvarez

John A Voltin

Scott M Smith

Joseph Yih Chang

A method and system within a data processing system are disclosed for halting execution of instructions by a processor in response to an enumerated occurrence of a selected combination of internal states within the processor. The processor includes a number of state machines and a means for monitoring the states of the number of state machines. According to the present invention, a selected combination of states of a subset of the state machines is specified. An enumerated occurrence of the selected combination of states of the subset of the state machines is then detected. In response to the enumerated occurrence of the selected combination of states, execution of instructions by the processor is halted such that states of the number of state machines within the processor remain substantially unchanged following the enumerated occurrence of the selected combination of states. In a first embodiment of the present invention, the selected combination of states is specified as a combination of states corresponding to an access to a specified address within an associated memory. According to a second embodiment of the present invention, the selected combination of states is specified as a selected sequence of states of a subset of the number of state machines.

Method and system for halting processor execution in response to an

A method and apparatus are provided for generating a ratioed clock signal. A first clock signal having a first frequency is output. At least one gating signal indicating ratio is output. In response to the first clock signal and the gating signal, a second clock signal is output. The second clock signal has a frequency that is substantially related to the first frequency by the ratio.

Apparatus and method for generating a clock in a microprocessor

A thresholding mechanism and method for performance monitoring of memory array access distribution times is disclosed. A data request signal sent to the memory hierarchy activates a first counter, having a first count value. A clock coupled to the first counter increments the first count value with each clock cycle, while also decrementing a decrementer having a predetermined threshold value. The first counter is deactivated by a completion signal when the data request is completed. A second counter having a second count value is incremented when the first count value is greater than the threshold value by the time the data request is complete.

Thresholding support in performance monitoring

A method and apparatus are provided for generating a phase-controlled clock signal within a microprocessor. A first clock signal having a first frequency is input. After a reset event, the first clock signal transitions in a first direction at a time t. A second clock signal is output having a second frequency related to the first frequency by a non-integer ratio. The second clock signal transitions in the same direction as the first clock signal at time t.

Apparatus and method for generating a phase-controlled clock signal

A data processing system including a processor that executes a plurality of instructions including at least one instruction that requires an external operation to be performed. The processor provides information for this external operation instruction to an external device and continues to execute instructions that do not require the results from this external operation. The external device receives the information from the processor, performs the external operation and provides the results to the processor. A further aspect of this data processing system is an interface that is interconnected between the processor and the external device. The processor provides the external operation information to the interface. The interface in turn provides the information to the external device and concurrently accesses data from the memory that will be required by the external device for performing the external operation.

Processor controlled DMA controller for transferring instruction and

In a data processing system, particularly one implemented by a microprocessor, apparatus is provided for bypassing the main parallel information bus between the processor and main storage unit by a serial information bus for testing purposes. Serial test information is applied through the serial information bus to a storage control unit which interfaces the processor and storage unit. The control includes circuitry for converting the information from the serial bus into the parallel format of the data which is provided from the processor along the main parallel bus. The test information applied has the same commands and address structure as the information output from the central processor. As a result, when the serial test information is converted to parallel format, by the apparatus, it will be indistinguishable from parallel data applied directly from the processor along the parallel bus.

Bidirectional serial test bus device adapted for control processing unit

A data processing system including several devices connected to an asynchronous communications bus for communications between these devices. The communications bus includes a protocol that requires only a single device to regulate communication between devices at any one time. This regulating device is termed the bus master and the remaining devices are termed slaves. This protocol provides the capability for a slave device to indicate to the bus master that a new bus master is to be designated for a temporary communication. This communication with a different bus master then occurs during the communication of the designated bus master.

Data processing system with overlap bus cycle operations

A plurality of controllers are connected to a common bus in turn connected to a central processor. Each of the controllers respectively serves as an interface between the central processor and at least one storage unit for input/output device. In order for the controllers to distinguish between addresses, the addresses sent from the central processor contain identifier segments indicative of the controller to which the address is being sent. Controllers in turn contain programmable comparison means for comparing the identifier segments in addresses to a stored controller identifier indicative of the controller. Because the comparison means are programmable, controller identifiers have to be set up each time the system is turned on. Consequently, the present invention provides such turn on or initialization means including a read-only initialization program stored in one of the storage units: the controller interfacing with this storage unit becomes a master controller; the master controller has apparatus which is selectively activated only during initialization for accepting all addresses irrespective of the identifier segment. The other controllers have apparatus selectively activated only during initialization for disabling the comparison means and such other controllers so that no addresses are accepted by the other controllers during the initialization. In other words, the comparison means in the master controller is completely bypassed during initialization whereby the read-only initialization program is accessed only through the master controller.

Initialization apparatus for a data processing system with a plurality

A plurality of data processor units are connected to a common bus which is connected to first and second interleaved storage units. The system is a synchronous one in which timing means establish a series of information transfer intervals. One or more of the processor units contain apparatus for selectively commencing an address transfer on the bus to one of the storage units during a transfer interval; the storage transaction initiated by the address transfer will require more than the one transfer interval to complete. One or more of the processors have means for monitoring the bus in order to determine whether an address on the bus has been transferred to the first or the second storage unit during a particular transfer interval. The address transfer apparatus further includes apparatus responsive to the monitoring apparatus for selectively transferring the next subsequent address to the other of said storage units to thus achieve alternating interleaving between storage units.

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Round Rock, TX, United States of America

Charles G Wright