Further information
Safety Manual for MPC5777M, Rev. 1.1
NXP Semiconductors 91
^ (((data_a2_is_one >> 9) & 1) ? 0x1c : 0x0) /* data[ 9] */
^ (((data_a2_is_one >> 8) & 1) ? 0x31 : 0x0) /* data[ 8] */
^ (((data_a2_is_one >> 7) & 1) ? 0x8c : 0x0) /* data[ 7] */
^ (((data_a2_is_one >> 6) & 1) ? 0x4a : 0x0) /* data[ 6] */
^ (((data_a2_is_one >> 5) & 1) ? 0x4c : 0x0) /* data[ 5] */
^ (((data_a2_is_one >> 4) & 1) ? 0x15 : 0x0) /* data[ 4] */
^ (((data_a2_is_one >> 3) & 1) ? 0x83 : 0x0) /* data[ 3] */
^ (((data_a2_is_one >> 2) & 1) ? 0x9e : 0x0) /* data[ 2] */
^ (((data_a2_is_one >> 1) & 1) ? 0x43 : 0x0) /* data[ 1] */
^ ((data_a2_is_one & 1) ? 0xc1 : 0x0); /* data[ 0] */
ecc = ecc ^ addr_ecc; /* combine data and addr ecc values */
return(ecc);
}
On a memory read operation, the E2E ECC logic performs the same type of optional adjustment on the
read checkbits.
As the ECC syndrome is calculated on a read operation by applying the H-matrix to the data plus the
checkbits, an all zero syndrome indicates an error free operation. If the generated syndrome value is
non-zero and matches one of the H-matrix values associated with the data or checkbits, it represents a
single-bit error correction case and the specific bit is complemented to produce the correct data value. If
the syndrome value matches one of the H-matrix values associated with the address bits, or is an even
weight value, or represents an unused odd weight value, a non-correctable ECC event has been detected
and the appropriate error termination response is initiated.
The preceding discussion has provided a generic overview of the end-to-end ECC strategy implemented
in this family of automotive MCUs.
7 Further information
7.1 Conventions and terminology
Table 21 shows the list of conventions for this document.
7.2 Acronyms and abbreviations
A short list of acronyms and abbreviations used in this document is shown in Table 22.
Table 21. List of conventions and terminology
Convention Description
error Discrepancy between a computed, observed, or measured value or condition and the true, specified
or theoretically correct value or condition.
fault Abnormal condition that may cause a reduction in, or loss of, the capability of a functional unit to
perform a required function.
failure The termination of the ability of a functional unit to perform a required function.
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