摘要:
Systems, method, and computer program products for utilizing a spare lane for additional checkbits. Systems include computer, storage or communications systems with bitlanes for transferring error correcting code (ECC) words in packets over a bus in multiple cycles, a spare bitlane available to the bus, a spared mode and an initial mode. The spared mode is executed when the spare bitlane has been deployed as a replacement bitlane for carrying data for one of the other bitlanes. The initial mode is executed when the spare bitlane has not been deployed as a replacement bitlane. The initial mode includes utilizing the spare bitlane for carrying one or more additional ECC checkbits. The initial mode provides at least one of a more robust error detecting function for the bus than the spared mode and a more robust error correcting function for the bus than the spared mode.
摘要:
An improved memory card and its use in a computer system is provided. The computer system has a system bus which provides requests from a CPU to a memory controller, which then provides signals to the memory card or module or a memory bus. The memory card is provided with first and second banks of DRAMs, a memory card bus and a DSP. Logic circuitry including a memory card data bus controller provides communication of the DSP with the banks of DRAM chips. Logic circuitry is also provided which can selectively connect the DSP to either the first or second bank of DRAMs and selectively connect the memory bus with the other bank of DRAMs or with both banks of DRAMs. Hence when the CPU is accessing one bank of DRAMS the DSP can access the other bank of DRAMs thus allowing the DSP to function utilizing the bank of DRAMs not being accessed by the memory bus to service the CPU or some I/O device.
摘要:
A memory module for attachment to a computer system having a memory bus and a method of using the memory module for error correction by scrubbing soft errors on-board the module is provided. The module includes a printed circuit card with memory storage chips on the card to store data bits and associated ECC check bits. Tabs are provided on the circuit card to couple the card to the memory bus of the computer system. Logic circuitry selectively operatively connects and disconnects the memory chip and the memory bus. A signal processor is connected in circuit relationship with the memory chips. The logic circuitry selectively permits the signal processor to read the stored data bits and associated check bits from the memory chips, recalculate the check bits from the read stored data bits, compare the recalculated check bits with the stored check bits, correct all at least one bit errors in the store data bits and stored associated check bits and re-store the correct data bits and associated check bits in the memory chips. When the memory chips and the memory bus are disconnected, single bit soft errors occurring during storage of the data bits and check bits are corrected periodically before the data is read from the memory chips to the data bus on a read operation.
摘要:
The disclosed invention relates generally to electronic data storage systems that access data storage memory modules via a data bus comprised of multiple data query lines and, more particularly, to an electronic data storage system provided with a data bus that can be selectively provided with terminations thereby permitting the data storage memory to use either modules that require that the data query lines be open-ended, i.e., without terminations or modules that require that the data bus be terminated and to a method for operating such a system. The present invention is particularly directed to a single memory system that can accommodate either 3.3V DIMMs or DDR DIMMs. This is especially accomplished by providing the processor circuit, used in memory storage systems, with both (3.3V) receiver/driver circuits and double rate (DDR) receiver/driver circuits, with an identification circuit for identifying the type of DIMMs in the memory system coupled thereto, a selection circuit for selecting the receiver/driver circuits required to access the identified DIMMs, and switch for adding or removing terminations to the data query lines, interconnecting the selected receiver driver circuits to identified DIMMS. Thus the invention provides a memory system that can access either 3.3V DIMMs or DDR DIMMs and automatically provide the proper terminations on the data bus used to access the DIMMs.
摘要:
A serial bus and connection to a device on a computer system through a system memory controller is provided on a memory card having a DSP and a memory bus controller to allow the DSP on the memory card to gain access to the system device without using the system memory bus. The serial bus is a two wire serial bus connecting the device to the DSP through the system memory controller. If more than one memory card is present with DSPs or more than one device is contending for access, the system memory controller or arbitrate the access of each memory card or contending device. In such case the serial bus will signal the system memory controller when it wants access to the particular device, and the system memory controller will act as arbitrator to grant or not grant access to the particular memory card or device requesting access. If access is granted the bus memory controller outputs the required control or command word on the serial bus followed by the address and the required data. This serial information is received by the system memory controller which packets it, and, upon completion, outputs the information rapidly on a parallel bus, e.g. a PCI bus to the device which needs the information.
摘要:
A high bandwidth DRAM is provided with two separate bus networks connecting the DRAM to a processor. One bus network is a high speed (e.g., 500 MHZ) 8:1 or 16:1 multiplexed I/O bus and the second is a slower (e.g., 64-bit) bus. The high-speed bus is used for example for graphic intensive applications which require fast access to large numbers of bits in the DRAM memory array. This of course results in higher power requirements. Since, not all applications require such large amounts of data to be transferred between the DRAM and the processor, the slower bus is provided for these less demanding applications such as word processors, spreadsheets, and the like. The slower bus requires less power to operate and therefore results in a power saving mode which, among other things, facilitates longer battery life.
摘要:
A Dynamic Random Access Memory (DRAM) with a burst length programmable as eight (8) or nine (9) bytes. The DRAM array is divided into two or more sub-arrays, with sub-array cells arranged in addressable rows and columns. When the DRAM is programmed in Normal mode, the burst length is 8 and the entire array address space is available for data storage. When the DRAM is programmed for error checking (ECC mode), the burst length is nine and the array is reconfigured with part of the array providing the ninth byte. The DRAM's address space is reduced by one-eighth in ECC mode. Preferably, all nine locations are in the same page, with each page being divided into eight equal portions. In Normal mode all eight equal portions are data storage; and, in ECC mode, seven-eighths of the page is data storage, the remaining one eighth being assigned to check bit storage.
摘要:
A method, system and computer program product implement memory performance management and enhanced memory reliability of a computer system accounting for system thermal conditions. When a primary memory temperature reaches an initial temperature threshold, reads are suspended to the primary memory and reads are provided to a mirrored memory in a mirrored memory pair, and writes are provided to both the primary memory and the mirrored memory. If the primary memory temperature reaches a second temperature threshold, write operations to the primary memory are also stopped and the primary memory is turned off with DRAM power saving modes such as self timed refresh (STR), and the reads and writes are limited to the mirrored memory in the mirrored memory pair. When the primary memory temperature decreases to below the initial temperature threshold, coherency is recovered by writing a coherent copy from the mirrored memory to the primary memory.
摘要:
A system and method for providing a memory device having a shared error feedback pin. The system includes a memory device having a data interface configured to receive data bits and CRC bits, CRC receiving circuitry, CRC creation circuitry, a memory device pad, and driver circuitry. The CRC receiving circuitry utilizes a CRC equation for the detection of errors in one or more of the received data and the received CRC bits. The CRC creation circuitry utilizes the CRC equation for the creation of CRC bits consistent with data to be transmitted to a separate device bits. The memory device pad is configured for reporting of any errors detected in the received data and the received CRC bits. The driver circuitry is connected to the memory device pad and merged with one or more other driver circuitries resident on one or more other memory devices into an error reporting line.
摘要:
A system and method for providing a memory device having a shared error feedback pin. The system includes a memory device having a data interface configured to receive data bits and CRC bits, CRC receiving circuitry, CRC creation circuitry, a memory device pad, and driver circuitry. The CRC receiving circuitry utilizes a CRC equation for the detection of errors in one or more of the received data and the received CRC bits. The CRC creation circuitry utilizes the CRC equation for the creation of CRC bits consistent with data to be transmitted to a separate device bits. The memory device pad is configured for reporting of any errors detected in the received data and the received CRC bits. The driver circuitry is connected to the memory device pad and merged with one or more other driver circuitries resident on one or more other memory devices into an error reporting line.