5.8.5. TCM read modify write

Read modify write can be enabled on the TCM interfaces by setting the ITCMCR.RMW or DTCMCR.RMW bits to 1, see Instruction and Data Tightly-Coupled Memory Control Registers. When enabled, the processor uses the read modify write sequence for writes that have a data size that are less than the width of the interface. This feature is intended to be used in systems that implement ECC in TCM.


When ECC is being used, the TCMs must be initialized at boot time. This is to avoid speculative and mispredicted access from triggering ECC attempts to correct single-bit errors and system fault response from spurious double-bit errors which, if real, might be unrecoverable.

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