HITACHI Deskstar & CinemaStar 7K1000.B & Deskstar E7K1000 Hard Disk Drive specification 
122 
11.9   Format Unit (F7h) 
 
Command Block Output Registers 
Command Block Input Registers 
   
Table 81    Format Unit Command (F7h) 
   
The Format Unit command initializes all user data sectors after merging reassigned sector  location into the 
defect information of the device and clearing the reassign information. Both new reassign information and new 
defect  information  are  available  right  after  command  completion  of  this  command.  Previous  information  of 
reassign and defect are erased from the device by executing this command. 
Note that the Format Unit command initializes from LBA 0 to Native MAX LBA regardless of setting by Initialize 
Device Parameter (91h) command, Device Configuration Overlay, or Set Max Address (F9h) command, so the 
protected area defined by these commands is also initialized. 
Security Erase Prepare (F3h) commands should be completed just prior to the Format Unit command. If the 
device receives a Format Unit command without a prior Security Erase Prepare command, the device aborts the 
Format Unit command. 
All  values  in  Feature register  are  reserved,  and  any  values  other  than  11h  should  not  be  put  into  Feature 
register. 
This command does not request to data transfer. 
Command execution time depends on drive capacity. To determine command timeout value, Word 89 of Identify 
Device data should be referred.