SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
ECC is a mechanism for providing increased system reliability (via reduction of memory soft errors) by allowing single bit errors to be detected and corrected and double bit errors to be detected.
One or more memories within VISS are ECC protected using an ECC Memory Wrapper which implements Single Error Correction and Double Error Detection (SECDED).
The ECC wrapper provides Single Error Detection and Correction (SED/SEC). This logic detects and corrects a single bit error (1 bit error per ECC word or per ECC data segment). For memories that contain critical and/or persistent data, automatic (immediate or delayed) write-back of the corrected data to the corresponding memory address is supported. In addition, the ECC wrapper also supports multiple options for partial word writes, such as read-modify-write or multiple ECC code segments per word.
The ECC wrapper also provides Double Error Detection (DED). This logic only detects (does not correct) double errors (2 bit errors per ECC word or per ECC data segment).
An ECC Aggregator at the VISS level consolidates the ECC configuration and status bits for all the ECC supported memories in the subsystem. It provides a single EOI-handshake based interrupt to the host (for both single and double error detections) and a standard 32-bit VBUSP interface for configuring and querying the various ECC wrappers via their ECC register set.
The following VISS memories are ECC protected:
For more information on the ECC Aggregator operation, see Section ECC Aggregator in Chapter Safety Modules.