Seagate ST3660A Product Manual - Page 38

30 Medalist XE Family Product Manual, Rev. B Disc errors encountered during Write Multiple commands are posted after the attempted disc write of the block or partial block transferred. The Write command ends with the sector in error, even if it was in the middle of a block. Subsequent blocks are not transferred in the event of an error. Interrupts are generated when DRQ is set to 1 at the beginning of each block or partial block. The contents of the Command Block registers are undefined when they follow the transfer of a data block that had a sector in error. The host should retry the transfer as individual requests to obtain valid error information. 3.4 Onboard drive diagnostics During startup, the drive executes a series of diagnostic tests. If the diagnostic tests detect an error, the drive LED indicates the nature of the error by emitting a flash code. A subset of the error flash codes is contained in the following table. Number of flashes Irregular flashes 2 3 4 5 Error code description Microprocessor error ROM checksum error External RAM error I/O chip error Buffer RAM error 3.5 ECC performance tests The drive does not report ECC errors when it performs on-the-fly error correction. This allows the drive to correct the data without sacrificing performance. Some older drive diagnostic utilities test the drive's ability to apply ECC by creating small data errors and then checking to see if these errors are reported. If you run one of these tests on a drive that is functioning properly, the test may report that the drive is failing to detect ECC errors. However, this does not mean that the drive is malfunctioning.