Datasheet

Command Specifications
4-190 C141-C008
(5) Mode = 0, 1, 0, 1 : Microcode download, with saving
In this mode, the controller’s microcode or control information is transferred to
the IDD’s control memory area and written to the disk. “0” must be specified in
the “Buffer ID” field and the “Buffer address” field.
The "Transfer byte length" field specifies the total number of transfer bytes of
data transferred from the INIT.
When all the data have been received, the IDD writes the new microcode to the
disk’s system area and operates in accordance with this microcode until new
microcode is downloaded.
When abnormal termination for reasons other than ILLEGAL
REQUEST [=5] / Invalid field in CDB [=24-00] or ILLEGAL
REQUEST [=5] / Invalid field in parameter list [=26-00] occurs, the
IDD indicates that downloading of the new microcode failed, and it
is therefore necessary for the INIT to quickly download the new
microcode.
When downloading of microcode is completed, the IDD generates a
UNIT ATTENTION condition for all the INITs except the INIT
that issued the WRITE BUFFER command. At this time, the sense
code indicates “Microcode has been changed [=3F-01].”
When the IDD is checked and downloading of the microcode is judged to be
possible, the IDD may be in the Not Ready state (the state in which the spindle
motor is not rotating). In this event, the IDD starts the motor, then saves the
microcode to flash ROM and the system area to disk media. Then, the IDD
stops the motor and returns to the Not Ready state.