摘要:
A computer system having central processors (CPs), an associated L2 cache, and processor memory arrays (PMAs), is provided with store logic and and fetch logic used to detect and correct data errors and to write the resulting data the associated cache. The store logic and and fetch logic blocks UEs from the cache for CP stores, for PMA (mainstore) fetches/loads, and for cache-to-cache loads, and with uncorrectable error recovery cache fetch and store logic injects `Special UEs` into the cache when loads cannot be blocked and abends CP jobs for UEs during CP stores, for UEs from PMA, for UEs from remote cache, and for UEs from local cache. This logic performs reconfiguring of memory when UEs are detected in memory and also blocks cache data propagation on UEs for CP fetches, for Cache-to-Cache transfer if data is unchanged, and for PMA castouts if data is unchanged, as well as forces castouts when UEs appear on changed cache data; injects `Special UEs` for UEs detected on changed cache data; invalidates the cache when UEs are detected in the local cache; and only deletes cache entries that have repeated failures.
摘要:
In an SMP computer system where data is partitioned across one or more chips a circuit and method permits detecting errors across chip boundaries due to a control error even though the ECC is not bad. A Multiple-input Shift-Register (MISR) on each bus is used to collect a dynamic signature representing all the critical buses on each chip that need to be compared. The MISR state combines present and previous states of these buses, so the MISR will be different if one or more bus controls break. Since an N-bit MISR shifts, comparing a single bit of the MISR each cycle guarantees detection within N cycles of a problem. The method of identifying errors includes accumulating bus signature information which is a function of current and previous values of an input bus and then comparing portions of the signatures of two or more input bus structures to determine sync of buses. Part of the signature is wrapped around into the signature to cause past information to be maintained indefinitely. Additional logic is introduced, including mask logic, programmable feedback, and counters along with a method of isolating defects using these features.
摘要:
A method for optimizing scan chains in an integrated circuit that has multiple levels of hierarchy addresses unlimited chains and stumps and separately all other chains and stumps. Unlimited chains and stumps are optimized by dividing an area encompassed by the chains and by a start point and an end point of the stump into a grid comprised of a plurality of grid boxes, and determining a grid box to grid box connectivity route to access all of the grid boxes between the start point and the end point by means of a computer running a routing algorithm. All other chains and stumps are optimized randomly assigning to a stump a chain that can be physically reached by that stump and adding an additional chain to that stump based on the number of latches in the additional chain, its physical location, and the number of latches already assigned.
摘要:
In an SMP computer system where data is partitioned across one or more chips a circuit and method permits detecting errors across chip boundaries due to a control error even though the ECC is not bad. A Multiple-input Shift-Register (MISR) on each bus is used to collect a dynamic signature representing all the critical buses on each chip that need to be compared. The MISR state combines present and previous states of these buses, so the MISR will be different if one or more bus controls break. Since an N-bit MISR shifts, comparing a single bit of the MISR each cycle guarantees detection within N cycles of a problem. The method for identifying errors includes accumulating bus signature information which is a function of current and previous values of an input bus and then comparing portions of the signatures of two or more input bus structures to determine sync of buses. Part of the signature is wrapped around into the signature to cause past information to be maintained indefinitely. Additional logic is introduced, including mask logic, programmable feedback, and counters along with a method for isolating defects using these features.
摘要:
Error detection and correction circuitry, optimized to reduce the time required to correct single errors and to detect the presence of uncorrectable errors, uses an optimized H-Matrix and provides reduced logic circuitry. Correctable error syndromes are defined as comprising an odd number of ones and an uncorrectable-error detection circuit generates an uncorrectable-error indication when an even number of ones are detected. The correctable-error syndromes are defined as having a predefined combination of ones and zeros in each of a set of corresponding bit positions and different combinations of ones and zeros in other bit position. An error syndrome comprising only zeros is designated as indicative of a no error condition. Logic circuitry is provided which implements the error detection and correction circuitry with a reduced set of logic gates.
摘要:
The process of laying out a floorplan for a clock control distribution network in an integrated chip design is simplified and the efficiency of a staging network created is improved. Rather than manually create the staging network in HDL or as a network description table while looking at a picture of the chip floorplan in a Cadence Viewer, an automated method which runs in the Cadence environment uses an algorithmic approach to the problem of maximizing the utilization of staging latches, eliminating unnecessary power and area usage. Efficiency is maximized by updating the Physical Layout directly with the staging solution arrived at by the algorithm.
摘要:
The process of laying out a floorplan for a clock control distribution network in an integrated chip design is simplified and the efficiency of a staging network created is improved. Rather than manually create the staging network in HDL or as a network description table while looking at a picture of the chip floorplan in a Cadence Viewer, an automated method which runs in the Cadence environment uses an algorithmic approach to the problem of maximizing the utilization of staging latches, eliminating unnecessary power and area usage. Efficiency is maximized by updating the Physical Layout directly with the staging solution arrived at by the algorithm.
摘要:
A scalable selector and method for a data processing system provides a multiple-bit, multiple bus selector logic for controling data routing and allowing dataflow to be connected and reconnected without change to control logic. The scalable selector logic includes a data selector controlled by the input controls as could accommodate controls from the Prior Art, as well providing an additional Orthogonality Checker to monitor for the condition where more than one control signal is active, and additional Data Valid logic to determine whether any of the input data buses has been selected to the output. The scalable selectors can be used in a switching network where these additional outputs operate as network controls allowing for the selection of buses in a switch network with orthogonality checking and data valid generation. The selectors also allow for swapping of data ports for timing and function sharing without impacting existing external control logic.
摘要:
SRAM macro sparing allows for full chip function despite the loss of one or more SRAM macros. The controls and data flow for any single macro within a protected group are made available to the spare or spares for that group. This allows a defective or failed SRAM macro to be shut off and replaced by a spare macro, dramatically increasing manufacturing yield and decreasing field replacement rates. The larger the protected group, the fewer the number of spares required for similar improvements in yield, but also the more difficult the task of making all the controls and dataflow available to the spare(s). In the case of the Level 2 Cache chip for the planned IBM Z6 computer, there are 4 protected groups with 192 SRAM macros per group. Each protected group is supplanted with an additional 2 spare SRAM macros, along with sparing controls and dataflow that allow either spare to replace any of the 192 protected SRAM macros.
摘要:
A method for optimizing scan chains in an integrated circuit that has multiple levels of hierarchy addresses unlimited chains and stumps and separately all other chains and stumps. Unlimited chains and stumps are optimized by dividing an area encompassed by the chains and by a start point and an end point of the stump into a grid comprised of a plurality of grid boxes, and determining a grid box to grid box connectivity route to access all of the grid boxes between the start point and the end point by means of a computer running a routing algorithm. All other chains and stumps are optimized randomly assigning to a stump a chain that can be physically reached by that stump and adding an additional chain to that stump based on the number of latches in the additional chain, its physical location, and the number of latches already assigned.