220.127.116.11.3. CRC_ERROR Pin Behavior
The Intel® Arria® 10 fast EDCRC feature runs all the column-based check-bits engine in parallel. When an SEU is detected, the column-based check-bits asserts the CRC_ERROR, the detected frame location is then passed to the frame-based check-bits to further localize the affected bit. This process causes the CRC_ERROR pin to assert twice. Column-based check-bits assert the first CRC_ERROR pulse and followed by the frame-based check-bits asserting the second pulse.
In Intel® Arria® 10, as soon as an SEU is detected, the CRC_ERROR is asserted high and remains high until the EMR is ready to be read. You can unload the EMR data as soon as the CRC_ERROR pin goes low. Once EMR data is unloaded, can determine the error type and the affected location. With these information you can decide how your system should respond to the specific SEU event.
In the rare event of an uncorrectable and un-locatable error, the CRC_ERROR signal is asserted only once. There is no second pulse assertion by frame-based check-bits due to the uncorrectable error location cannot be located. The statistical likelihood of uncorrectable multi-bit SEU is less than one in 10,000 years for a device in typical environmental conditions.
Example of CRC_ERROR pin behavior for column-based/frame-based check-bits with a single pulse observed in one SEU event.