Seagate ST3660A Product Manual - Page 37

Medalist XE Family Product Manual, Rev. B 29 If the number of requested sectors is not evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial block transfer. The partial block transfer is for n sectors, where n = remainder (sector count / block count) If the Read Multiple command is attempted before the Set Multiple Mode command has been executed or when Read Multiple commands are disabled, the Read Multiple operation is rejected with an Aborted Command error. Disc errors encountered during Read Multiple commands are posted at the beginning of the block or partial block transfer, but DRQ is still set and the data transfer takes place as it normally would, including transfer of corrupted data, if any. The contents of the Command Block registers, following the transfer of a data block that had a sector in error, are undefined. The host should retry the transfer as individual requests to obtain valid error information. Subsequent blocks or partial blocks are transferred only if the error was a correctable data error. All other errors cause the command to stop after the block containing the error is transferred. 3.3.5 Write Multiple command (C5H) This command (command code C5H) is similar to the Write Sectors command. Interrupts are not presented on each sector but on the transfer of a block that contains the number of sectors defined by Set Multiple Mode command. The number of sectors per block to be transferred without intervening interrupts is programmed by the Set Multiple Mode command, which must be executed before the Write Multiple command. When the Write Multiple command is issued, the Sector Count register contains the number of sectors (not the number of blocks or the block count) requested. If the number of requested sectors is not evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial-block transfer. The partial-block transfer is for n sectors, where n = remainder (sector count / block count) If the Write Multiple command is attempted before the Set Multiple Mode command has been executed or when Write Multiple commands are disabled, the Write Multiple operation is rejected with an aborted command error.