Spectra Logic Spectra S50 User Manual page 99

Table A-17: Segment Descriptor for Codes 03h and 0Eh
Bit
Byte 7
16 (MSB)
17
18
19
The Source Device Transfer Length specifies the amount of data to be read from the
source stream device on each read operation. See Table A-12 on page 92 for
information on how the segment descriptor Source Device Transfer Length interacts
with the Tape Block Length Parameter of the device-specific information.
The Destination Device Transfer Length specifies the amount of data to be written to
the destination stream device on each write operation. See Table A-12 on page 92 for
information on how the segment descriptor Destination Device Transfer Length
interacts with the Tape Block Length Parameter of the device-specific information.
The Transfer Count field specifies the number of read/write operations that must be
executed for this segment descriptor. The DC bit is used to indicate whether the
Transfer Count field refers to the source or destination logical unit. A DC bit of 0
indicates that the Transfer Count field refers to the source logical unit. A DC bit of 1
indicates that the Transfer Count field refers to the destination logical unit.
Appendix A. Extended Copy—83h—143r1 Specifications
6 5 4 3 2
Transfer Count
99
1 0
(LSB)