Abstract: A system and method for recording trace data while conserving cache resources includes generating trace data and creating a cache line containing the trace data. The cache line is assigned a tag which corresponds to an intermediate address designated for processing the trace data. The cache line also contains embedded therein an actual address in memory for storing the trace data, which may include either a real address or a virtual address. The cache line may be received at the intermediate address and parsed to read the actual address. The trace data may then be written to a location in memory corresponding to the actual address. By routing trace data through a designated intermediate address, CPU cache may be conserved for other more important or more frequently accessed data.

Abstract: A method, apparatus and program storage device for providing clocks to multiple frequency domains using a single input clock of variable frequency. Independent clock signals are generated at predetermined clock frequency targets in response to control signals that are based on a determined bus clock frequency.

Abstract: A diagnostic tracing logger is presented for use in a multithread environment in which diagnostic trace log entries are captured and recorded. The trace logs are composed of sequences of memory addresses used to access instructions and operands, instruction op-codes and register specifiers, sequences of memory addresses, branch instructions or exceptions, the contents of registers or semiconductor memory locations, and the like. In one embodiment, a software module configures a plurality of buffers to capture bus traces, each trace triggered by a specific pattern. A buffer controller manages transfer of diagnostic trace information from the plurality of buffers to a diagnostic log without using processor memory cycles. The trace information is transferred to a selected buffer using a processor cache flush instruction. Diagnostic trace logging facilitates diagnosis of complex system and software interactions without the cost and overhead of prior art trace logging techniques.

Abstract: A data initiator device designates an initial data tag set for tagging data transfers to thereby attach data tags from the designated set to commands directed to data transfers between the data initiator device and a data target device subsequent to the designation of the initial data tag set. The data transfer commands are issued with the attached data tags from the designated data tag set until an occurrence of a reset error associated with one of the issued data transfer commands. In response to the reset error, the data initiator device designates a different data tag set for tagging data transfers to thereby attach data tags from the newly designated data tag set to commands directed to data transfers between the data initiator device and the data target device subsequent to the designation of the new data tag set.

Abstract: A method, apparatus, and program storage device for providing clocks to multiple frequency domains using a single input clock of variable frequency. Independent clock signals are generated at predetermined clock frequency targets in response to control signals that are based on a determined bus clock frequency.

Abstract: An apparatus, system and method are disclosed for storing modified data. The apparatus includes a battery source for supplying backup power. The apparatus also includes a memory module for storing data. The memory module includes a backup portion and a non-backup portion. Only the backup portion is backed up by the battery source in the event of a power failure. A data flow module controls data flow into and out of the memory module. The data flow module stores modified data exclusively in the backup portion of the memory module.

Abstract: A method, apparatus and program storage device for automatically presenting status from a host bus adapter until an error is detected is provided. Data is transmitted between the host bus adapter and a host. The host performs data transmission validation and determines whether data transmission was successful. The host bus adapter automatically sends status information when data transmission was successful, else the host bus adapter waits for status type identification from the host for transmission of data.

Abstract: A method and apparatus for increasing the processing speed of processors and increasing the data hit ratio is disclosed herein. The method increases the processing speed by providing a non-L1 instruction caching that uses prefetch to increase the hit ratio. Cache lines in a cache set are buffered, wherein the cache lines have a parameter indicating data selection characteristics associated with each buffered cache line. Then which buffered cache lines to cast out and/or invalidate is determined based upon the parameter indicating data selection characteristics.

Abstract: Provided are a method, system, and program for an adaptor to read and write to system memory. A plurality of blocks of data to write to storage are received at an adaptor. The blocks of data are added to a buffer in the adaptor. A determination is made of pages in a memory device and I/O requests are generated to write the blocks in the buffer to the determined pages, wherein two I/O requests are generated to write to one block split between two pages in the memory device. The adaptor executes the generated I/O requests to write the blocks in the buffer to the determined pages in the memory device.

Abstract: A method, apparatus and program storage device for performing a self-healing cache process is described. At least one error affecting a cache is detected. The cache may have a matching address tag for a fetching operation. Based on the type of error, a self-healing cache process is performed based.

Abstract: A data initiator device designates an initial data tag set for tagging data transfers to thereby attach data tags from the designated set to commands directed to data transfers between the data initiator device and a data target device subsequent to the designation of the initial data tag set. The data transfer commands are issued with the attached data tags from the designated data tag set until an occurrence of a reset error associated with one of the issued data transfer commands. In response to the reset error, the data initiator device designates a different data tag set for tagging data transfers to thereby attach data tags from the newly designated data tag set to commands directed to data transfers between the data initiator device and the data target device subsequent to the designation of the new data tag set.

Abstract: A method, apparatus and program storage device for providing self-quiesced logic for handling an error recovery instruction such as a reset or self-test instruction. For example, during a reset or self test procedure, the logic is isolated without adversely affecting the local processor. Self-quiesced logic processes an error recovery instruction by monitoring the processor interface for an idle condition and withholding access to the local processor. Once the local processor interface has been quiesced and the internal logic paths are idle, the logic will proceed with the reset or self-test.

Abstract: A method, apparatus and program storage device for managing dataflow through a processing system is disclosed. A buffer monitor maintains and monitors a buffer full threshold to control the write throughput to a data bus.

Abstract: A diagnostic tracing logger is presented for use in a multithread environment in which diagnostic trace log entries are captured and recorded. The trace logs are composed of sequences of memory addresses used to access instructions and operands, instruction op-codes and register specifiers, sequences of memory addresses, branch instructions or exceptions, the contents of registers or semiconductor memory locations, and the like. In one embodiment, a software module configures a plurality of buffers to capture bus traces, each trace triggered by a specific pattern. A buffer controller manages transfer of diagnostic trace information from the plurality of buffers to a diagnostic log without using processor memory cycles. The trace information is transferred to a selected buffer using a processor cache flush instruction. Diagnostic trace logging facilitates diagnosis of complex system and software interactions without the cost and overhead of prior art trace logging techniques.

Abstract: A method, apparatus and program storage device for automatically presenting status from a host bus adapter until an error is detected is provided. Data is transmitted between the host bus adapter and a host. The host performs data transmission validation and determines whether data transmission was successful. The host bus adapter automatically sends status information when data transmission was successful, else the host bus adapter waits for status type identification from the host for transmission of data.

Abstract: A method, apparatus and program storage device for providing clocks to multiple frequency domains using a single input clock of variable frequency. Independent clock signals are generated at predetermined clock frequency targets in response to control signals that are based on a determined bus clock frequency.

Abstract: A method, apparatus and program storage device for providing data integrity using check data and other metadata on a formatted storage medium.

Abstract: A method and apparatus for increasing the processing speed of processors and increasing the data hit ratio is disclosed herein. The method increases the processing speed by providing a non-L1 instruction caching that uses prefetch to increase the hit ratio. Cache lines in a cache set are buffered, wherein the cache lines have a parameter indicating data selection characteristics associated with each buffered cache line. Then which buffered cache lines to cast out and/or invalidate is determined based upon the parameter indicating data selection characteristics.

Abstract: A shared bus arbitration scheme for a data communication system is provided, where a shared bus is connected to a plurality of bus masters and resources, some resources having higher priority than the others and including a peripheral device. Each master may request control of the shared bus and is adapted to perform short transfers and long burst transfers on the shared bus between a resource and the master. A shared bus arbiter is utilized for dynamically determining the highest priority request between a number of shared bus requests, and granting control of the shared bus to the highest priority requesting bus master.

Abstract: A shared bus hang prevention and recovery scheme for a data communication system is provided, where a shared bus is connected to a plurality of bus masters and corresponding slaves and located between an external bus connected to a system processor, and an internal bus connected to an internal processor. Some of the masters are associated with the external bus and others are associated with the internal bus, and one of the bus masters is a control master associated with the internal processor. The scheme utilizes a shared bus hang prevention and recovery device having a circuitry and a control code. The circuitry is timing each pending request of the control master for the shared bus and initiating bus recovery if the shared bus is hung up, when the control master exceeded a pre-determined time period allowed for waiting to acquire the shared bus control and complete the transfer on the shared bus.