Hitachi HTS542525K9SA00 Specifications page 160

In reloading new microcode, the device does DASP handshake in reloading new microcode. Thus the device does
not recognize the slave device even though it exists. Also when the spin-up of the device is disabled, the device
spins down after reloading new microcode.
A Features register value of 03h indicates that the microcode will be transferred in two or more Download Micro-
code commands using the offset transfer method. The buffer offset value is defined by the value in Cylinder regis-
ters. The buffer offset value is the starting location in the microcode file, which varies in 512 byte increments.
All microcode segments shall be sent to the device in sequence.
The device may abort the DOWNLOAD MICROCODE command and discard all previously downloaded
Microcode, if the current buffer offset is not equal to the sum of the previous DOWNLOAD MICROCODE
command buffer offset and the previous sector count. The first DOWNLOAD MICROCODE command shall
have a buffer offset of zero.
The new firmware should become effective immediately after the transfer of the last data segment has
completed.
When the device detects the last download microcode command for the firmware download the device shall
perform any device required verification and save the complete set of downloaded microcode.
If the device receives a command other than download microcode prior to the receipt of the last segment the
new command is executed and all previously downloaded microcode is discarded.
If a software or hardware Reset is issued to the device before all of the microcode segments have been
transferred to the device the device shall abandon all of the microcode segments received and process the
Reset.
Deskstar 7K160 Hard Disk Drive Specification
146