HP Surestore 80fx Optical Drive and Library SCSI-2 Command Reference - Page 25

Table 1-2 SCSI Command Overview Drive Control Commands Command Complete 00H This message is sent from the target to the initiator to indicate that the execution of a command has terminated and that valid status has been sent to the initiator. After successfully sending this message, the target goes to the Bus Free Phase by releasing BSY (Busy). Extended Message 01H This message is sent from either the initiator or the drive to indicate that the message is an extended message. The drive supports only the synchronous data transfer request (SDTR) message. An SDTR message exchange will be initiated by a SCSI device when an arranged data transfer agreement becomes invalid. The agreement becomes invalid after an intermediate status such as: • Hard reset condition • BUS DEVICE RESET message • Wide data transfer message • Power cycle The initiator may also initiate a SDTR message exchange when appropriate to negotiate a new data transfer agreement (synchronous or asynchronous). Extended Message Format Byte 0 1 2 3 4 7 6 5 4 3 2 1 0 Extended Message (01H) Extended Message Length (03H) Synchronous Data Transfer Request Code (01H) Transfer Period Factor (m times 4 nanoseconds) REQ/ACK Offset (x) 1-6 Chapter 1