Motorola MVME172 - Manual (Page 296)

5-6 Computer Group Literature Center Web Site
MCECC
5
Triple (or Greater) Bit Error (Cycle Type = Burst Read or Non-Burst Read)
Some of these errors are detected correctly and are treated the same as a
double bit error. The rest could show up as "no error" or "single bit error",
both of which are incorrect.
Cycle Type = Burst Write
Because all of the bits are written during a burst write, no checking is done.
Single Bit Error (Cycle Type = Non-Burst Write)
Correct the data read from the DRAM, merge with the write data, and write
the correct, merged data to the DRAM.
Terminate the cycle normally. (Assert TA to the local bus.)
Log the error if one has not already been logged.
Notify the local MPU via interrupt if so enabled.
Double Bit Error (Cycle Type = Non-Burst Write)
Do not perform the write portion of the cycle. This causes the location to
continue to indicate non-correctable error when accessed.
Terminate the cycle normally. (Assert TA to the local bus.)
Log the error if one has not already been logged.
Notify the local MPU via interrupt if so enabled.
Triple (or Greater) Bit Error (Cycle Type = Non-Burst Write)
Some of these errors are detected correctly and are treated the same as a
double bit error. The rest could show up as "no error" or "single bit error",
both of which are incorrect.
Single Bit Error (Cycle Type = Scrub)
Write corrected data to the DRAM.
Log the error if one has not already been logged.