You can detect the presence of back blocks from a failed flash operation (such as an Erase) or an invalid Write operation (discovered through an invalid Error Correction Code, or ECC).

如果 flash 操作（例如 Erase）失败，或者 Write 操作无效（通过无效的错误校正代码发现，Error Correction Code，ECC），那么说明出现了坏块。

youdao

A sector includes user data and overhead data, such as an Error Correction Code (ECC) that has been calculated from the user data of the sector.

扇区包含用户数据和额外开销数据，例如已依据扇区的用户数据计算的错误校正码(ECC)。

youdao

The flagship Quadro 5010M features Error Correction Code (ECC) and fast, 64-bit double precision capabilities to ensure the greatest accuracy and fidelity of results.

ENGADGET: NVIDIA debuts new slew of Quadro mobile GPUs, each sporting Optimus for battery life too