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MIPS R10000 Microprocessor User Guide, Version 2.0
(document number: 007-2490-001 / published: 1997-01-30)    table of contents  |  additional info  |  download
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9. Error Protection and Handling

9.2 Uncorrectable Errors


Uncorrectable errors consist of:

  • Primary instruction cache array parity errors
  • Primary data cache array parity errors
  • Secondary cache tag array uncorrectable ECC errors
  • Secondary cache data array uncorrectable ECC errors
  • System interface command bus parity errors
  • System interface address/data bus uncorrectable ECC errors
  • System interface response bus parity errors

When the processor detects an uncorrectable error, a Cache Error exception is posted. In general, the detection of an uncorrectable error does not disrupt any ongoing operations. However, the instruction fetch and load/store units never use data which contains an uncorrectable error.


To inform the external agent, the processor asserts SysUncErr* for one SysClk cycle whenever any of the following uncorrectable errors are detected:

  • Primary instruction cache tag array parity errors
  • Primary data cache tag array parity errors
  • Secondary cache tag array uncorrectable ECC errors
  • System interface command bus parity errors
  • System interface address/data bus external address cycle uncorrectable ECC errors
  • System interface response bus parity errors.
The processor informs the external agent that an uncorrectable tag error has been detected by asserting
SysUncErr* for one SysClk cycle.




Copyright 1996, 1997, MIPS Technologies, Inc. -- 09 DEC 96


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MIPS R10000 Microprocessor User Guide, Version 2.0
(document number: 007-2490-001 / published: 1997-01-30)    table of contents  |  additional info  |  download


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