SCSI Command Lengths
Originally the most significant 3 bits of a SCSI opcode specified the length of the CDB. However, when variable-length CDBs were created this correspondence was changed, and the entire opcode must be examined to determine the CDB length. The lengths are as follows:
| Opcode (hex ) | Length |
|---|---|
| 00h to 1Fh | 6 |
| 20h to 5Fh | 10 |
| 60h to 7Dh | reserved |
| 7Eh | variable (more than 16 bytes) |
| 7Fh | extended (variable length; may contain one or more CDBs) |
| 80H to 9Fh | 16 |
| A0h to BFh | 12 |
| C0h to FFh | vendor specific |
Read more about this topic: SCSI Command
Famous quotes containing the words command and/or lengths:
“You must neither add anything to what I command you nor take away anything from it, but keep the commandments of the LORD your God with which I am charging you.”
—Bible: Hebrew, Deuteronomy 4:2.
“You’ll see certain Pythagoreans whose belief in communism of property goes to such lengths that they pick up anything lying about unguarded, and make off with it without a qualm of conscience as if it had come to them by law.”
—Desiderius Erasmus (c. 1466–1536)