SECDED
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SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
F021 Level 2 Flash Module Controller (L2FMC)
7.4
SECDED
The Flash memory can be protected by Single Error Correction Double Error Detection (SECDED). This
protection is enabled by the SECDED circuit inside of the bus master.
7.4.1 SECDED Initialization
Flash error detection and correction is enabled at reset.
The ECC values for all of the Flash memory space (Flash banks 0 through 6) must be programmed into
the Flash before the program/data can be read. This can be done by generating the correct values of the
ECC with an external tool such as
or may be generated by the programming tool. The Cortex
R5F CPU may generate speculative fetches to any location within the Flash memory space. A speculative
fetch to a location with invalid ECC, which is subsequently not used, will not create an abort, but will set
the ESM flags for a correctable or uncorrectable error. An uncorrectable error will unconditionally cause
the nERROR pin to toggle low. Therefore care must be taken to generate the correct ECC for the entire
Flash space including the holes between sections and any unused or blank Flash areas.
The Cortex R5F CPU does not generate speculative fetches into the address space of bank 7, the
EEPROM Emulation Flash. Therefore, it is only necessary to initialize the ECC values of the locations that
will be intentionally read by the CPU or other bus masters.
7.4.2 ECC Encoding
Twenty-nine address lines are also included in the ECC calculation. A failure of a single address line
inside of the bank will result in an uncorrectable error at the bus master. The ECC encoding is shown in