The result of the last self test. Represented as a sum of
a bit map. The variable bit positions are:
1 - Flash Checksum bad. Catastrophic error.
2 - EPROM Checksum bad. Catastrophic error.
4 - RAM Tests failed. Catastrophic error.
8 - ROM Checksum bad. Catastrophic error.
16 - DteLoss. Could not put DTE into loopback.
NonCatastrophic error.
32 - patternLossDuringTest. Put DTE into loopback but found
BERT errors. NonCatastrophic error.