Command Specifications
246 C141-C013
4.4 Maintenance, Diagnostic Commands 4.4.1 SEND DIAGNOSTIC (1D)
Bit
Byte 7 6 5 4 3 2 1 0
0 X'1D'
1 SELF-TEST CODE PF 0 SelfTest DevOfl UnitOfl
2 0 0 0 0 0 0 0 0
3 Parameter List Length (MSB)
4 Parameter List Length (LSB)
5 0 0 0 0 0 0 0 0
This command executes self-diagnosis tests which the HDD is equipped to
perform and operation specified in the parameter list transferred from the INIT.
(1) Self-diagnosis test
When the "SelfTest (self test)" bit is "1," and "Self-Test Code" field is "000" in
the CDB, this command specifies execution of the self-diagnosis test which the
HDD is equipped to perform. At this time, the "PF (page format)" bit and the
"Parameter list length" field in the CDB have no meaning and the values specified
there are disregarded. Also, the "DevOfl (device off-line)" bit specifies whether
or not operations which have an influence on the status of logical units other than
the logical unit specified in this command during the self-diagnosis test, but in the
HDD, there is only 1 logical unit that exists. Therefore, the specification in this
bit has no meaning and the specified value is disregarded.
The INIT can specify the type of self-diagnosis test to be executed through the
"UnitOfl (unit off-line)" bit. When "1" is specified in the "SelfTest (self test)" bit,
the HDD executes a series of self-diagnosis tests in accordance with the
combination with the "UnitOfl (unit off-line)" bit, as shown in Table 4.47.