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. The control code is used for monitoring and controlling the circuitry and terminating the transfer in progress causing the shared bus hang-up. During the bus recovery the circuitry prevents bus request grants to the master attached to the external bus until the master subsequent reset, and the control program instructions initiates transfers for all pending requests for the shared bus from the control master queue. Each transfer is being timed and terminated if the shared bus is hung up again. Upon the control master queue clearing, the internal processor executes the control program instructions to reset and reinitialize all masters and slaves on the shared bus.
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. The arbiter utilizes a three-level priority hierarchy arbitration scheme where the highest priority level is given to short message transfer requests on the higher-priority system resources, the intermediate priority level is given to short message transfer requests on the lower-priority system resources, if there are no outstanding higher priority level requests, and the lowest priority level is given for long burst transfers, if there are no outstanding short message transfer requests.
Abstract:
An apparatus and method for distinguishing correctable bit errors in memory. A bit error detection module detects a correctable bit error in a memory in response to a READ operation. The correctable bit error is correctable using error-correcting code. The READ operation is generated during normal operation. A comparison module compares an error location indicator with a stored error location indicator. The error location indicator includes a memory location of the correctable bit error. The stored error location indicator corresponds to a previously stored error location indicator of a previous correctable bit error. A storage module stores the error location indicator if the comparison module determines that the error location indicator differs from a stored error location indicator. An error counter module increases an error counter corresponding to the error location indicator if the comparison module determines that the error location indicator matches a stored error location indicator.
Abstract:
An apparatus, system, and method are disclosed for distinguishing correctable bit errors in memory. A bit error detection module detects a correctable bit error in memory. The correctable bit error is correctable using error-correcting code (“ECC”). A comparison module compares an error location indicator with a stored error location indicator. The error location indicator is a location of the correctable bit error. The stored error location indicator includes to at least one previously stored error location indicator of a previously detected correctable bit error. A storage module stores the error location indicator in response to the comparison module determining that the error location indicator differs from a stored error location indicator. A bit error counter module increases a random bit error counter if the comparison module determines that the error location indicator differs from a stored error location indicator and does not increase the random bit error counter otherwise.
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:
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:
One embodiment of an adapter card in accordance with the invention includes a circuit board connectable to a motherboard of a computer system. A logic chip is connected to the circuit board to provide functionality to the adapter card. One or more programmable devices are connected to the circuit board and store data read by the logic chip upon initialization. This data may include first character data to program the logic chip to have a first character and second character data to program the logic chip to have a second character. A switching mechanism is provided to switch between the first and second character data in response to an external input, thereby causing the logic chip to read one of the first and second character data.
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 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.