Samsung 3.5" hard disk drives 사용자 설명서

DISK DRIVE OPERATION 
 

SpinPoint V40 Product Manual 

70

 
This command enables the drive to perform Read and Write Multiple operations and establishes the block 
count for these commands. Refer to section 6.6.3 for the protocol. 
 
The Sector Count register is loaded with the number of sectors per block. Drives support block sizes of 2, 4, 
8, and 16 sectors. Upon receipt of the command, the drive sets BSY=1 and checks the Sector Count register. 
 
If the Sector Count register contains a valid value and the block count is supported, the value is loaded for all 
subsequent Read Multiple and Write Multiple commands and execution of those commands is enabled. If a 
block count is not supported, an Aborted Command error is posted, and Read Multiple and Write Multiple 
commands are disabled. 
 
If the Sector Count register contains 0 when the command is issued, Read and Write Multiple commands are 
disabled. At power-on, or after a hardware reset, the default mode is Read and Write Multiple disabled. And 
on software reset, the default mode of Read and Write Multiple will not be changed. 
 

 
This command is the only way to cause the drive to enter Sleep Mode. The drive is spun down, and when it is 
stopped, BSY is cleared, an interrupt is generated, and the interface becomes inactive. 
 
The only way to recover from Sleep mode without a reset or power-on is for the host to issue a software reset. 
 
A drive shall not power-on in Sleep Mode nor remain in Sleep Mode following a reset sequence. If the drive 
is already spun down, the spin down sequence is not executed.