Memory error correction system
First Claim
1. In a computer system having a processing unit, memory, memory control unit, system communication bus, and bus control unit, a method of correcting memory errors, comprising the steps of, detecting a data error while data is being transferred from memory to the system bus and generating corresponding corrected data if a data error is detected, storing at the memory control unit at least the address field and source identification code associated with the just detected data error, generating a bus request signal coupled to the bus control unit, said bus control unit, in turn, generating a bus grant signal, said memory control unit in response to said bus grant signal issuing a read message on the system bus having an address field and destination identification code corresponding to said stored address field and source identification code, and in response to said read message, the device indicated by said identification code, writing back to memory the correct data corresponding to said address field.
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Abstract
A system for correcting soft memory failures such as alpha particle failures in a dynamic random access memory and in a computer system wherein writeback caches are employed in a system bus environment. The address field and source identification code associated with a detected data error are stored. A generic bus request signal is generated and upon a bus grant a read message is issued on the system bus having an address field and destination address code corresponding to the stored address field and source identification code. In response to the read message, the device indicated by the identification code writes back to memory the correct data corresponding to the address field.
64 Citations
42 Claims
- 1. In a computer system having a processing unit, memory, memory control unit, system communication bus, and bus control unit, a method of correcting memory errors, comprising the steps of, detecting a data error while data is being transferred from memory to the system bus and generating corresponding corrected data if a data error is detected, storing at the memory control unit at least the address field and source identification code associated with the just detected data error, generating a bus request signal coupled to the bus control unit, said bus control unit, in turn, generating a bus grant signal, said memory control unit in response to said bus grant signal issuing a read message on the system bus having an address field and destination identification code corresponding to said stored address field and source identification code, and in response to said read message, the device indicated by said identification code, writing back to memory the correct data corresponding to said address field.
- 11. A memory error correction system for use in a computer apparatus having a plurality of processors, a system bus operatively connected to the plurality of processors, a memory susceptible to having soft memory failures, and memory controller means operatively connected to the memory, said system comprising, means for detecting a data error while data is being transferred from memory to the system bus and for correcting that transferred data if a data error is detected, means for storing at least the address field and source identification code associated with the just detected data error, means responsive to data error detection for generating a generic bus request signal, means responsive to said bus request signal for providing a bus grant signal, means responsive to the bus grant signal for issuing a read message on the system bus having an address field and destination identification code corresponding to said stored address field and source identification code, and means responsive to said read message for writing back to memory the correct data corresponding to said address field.
- 21. In a computer system having a processing unit, memory, memory control unit, a system communication bus, and bus control unit, a method of correcting memory errors, comprising the steps of, detecting a data error while data is being transferred from memory to the system bus and generating corresponding corrected data if a data error is detected, storing at the memory control unit at least the address field associated with the just detected data error, generating a bus request signal coupled to the bus control unit, said bus control unit, in turn, generating a bus grant signal, said memory control unit in response to said bus grant signal issuing a read message on the system bus having an address field corresponding to said stored address field, and in response to said read message, writing back to memory the correct data corresponding to said address field.
- 31. A memory error correction system for use in a computer apparatus having a plurality of processors, a system bus operatively connected to the plurality of processors, a memory susceptible to having soft memory failures, and memory controller means operatively connected to the memory, said system comprising, means for detecting a data error while data is being transferred from memory to the system bus and for correcting that data if a data error is detected, means for storing at least the address field associated with the just detected data error, means responsive to the data error detection for generating a generic bus request signal, means responsive to said bus request signal for providing a bus grant signal, means responsive to the bus grant signal for issuing a read message on the system bus having an address field corresponding to said stored address field, and means responsive to said read message for writing back to memory the correct data corresponding to said address field.
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41. A method of correcting memory errors, comprising the steps of, detecting a data error while data is being transferred from memory and generating corresponding corrected data if a data error is detected, storing at least the address field and source identification code associated with the just detected data error, generating a bus request signal, generating a bus grant signal in response to the bus request signal, issuing a read message in response to the bus grant signal on the system bus having an address field and destination identification code corresponding to said stored address field and source identification code, and in response to said read message, a device indicated by said identification code, writing in the memory the correct data corresponding to said address field.
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42. A method of correcting memory errors, comprising the steps of, detecting a data error in data stored in memory and generating corresponding corrected data if a data error is detected, storing at least the address field associated with the just detected data error, generating a bus request signal, generating a bus grant signal in response to the bus request signal, issuing a read message in response to the bus grant signal on the system bus having an address field corresponding to said stored address field, and in response to said read message, writing in the memory the correct data corresponding to said address field.
Specification