SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
This section provides information for both single-bit data errors and single-bit ECC check bit errors. If there is a single bit flip (0 to 1 or 1 to 0) in Flash data or in ECC data, then it is considered as a single-bit data error. The SECDED module detects and corrects single-bit errors, if any, in the 64-bit Flash data or eight ECC check bits read from the Flash/ECC memory map before the read data is provided to the CPU.
When SECDED finds and corrects single bit data errors, the following information is logged in the ECC registers if the ECC feature is enabled:
When the ERR_CNT value equals THRESHOLD+1 value and a single bit error occurs, the SINGLE_ERR_INT flag is set, and an interrupt (FLASH_CORRECTABLE_ERR on C28x PIE has to be enabled for interrupt, if needed) is fired. The SINGLE_ERR interrupt is not fired again until the SINGLE_ERR_INTFLG is cleared. If the single error interrupt flag is not cleared using the corresponding error interrupt clear bit in the ERR_INTCLR register, the error interrupt does not come again, as this is an edge-based interrupt.
When multiple single-bit errors get caught by ECC logic, Flash ECC registers hold the information related to the latest ECC error. When multiple single-bit errors get caught, both FAIL_0_L and FAIL_1_L (and/or FAIL_0_H and FAIL_1_H) might get set, indicating that single-bit fail0/fail1 occurred in different 64-bit aligned addresses.
Although ECC is calculated on 64-bit basis, a read of any address location within a 128-bit aligned Flash memory causes the single-bit error flag to get set when there is a single-bit error in both or in either one of the lower 64 and upper 64 bits (or corresponding ECC check bits) of that 128-bit data.