Fujitsu MHT2080AH - 80GB 5400 RPM PATA Hard Drive Product Manual page 119

This command allows the maximum address accessible by the user to be set in
LBA or CHS mode. Upon receipt of the command, the device sets the BSY bit
and saves the maximum address specified in the DH, CH, CL and SN registers.
Then, it clears BSY and generates an interrupt.
The new address information set by this command is reflected in Words 1, 54, 57,
58, 60 and 61 of IDENTIFY DEVICE information. If an attempt is made to
perform a read or write operation for an address beyond the new address space, an
ID Not Found error will result.
When SC register bit 0, VV (Value Volatile), is 1, the value set by this command
is held even after power on and the occurrence of a hard reset. When the VV bit is
0, the value set by this command becomes invalid when the power is turned on or
a hard reset occurs, and the maximum address returns to the value most lately set
when VV bit = 1. (The value by VV bit = 0 is held in case that this command
with VV bit = 1 has not been issued or had set the default value, and hard reset
occurs.)
After power on and the occurrence of a hard reset, the host can issue this
command only once when VV bit = 1. If this command with VV bit = 1 is issued
twice or more, any command following the first time will result in an Aborted
Command error.
When the SET MAX ADDRESS EXT command is executed, all SET MAX
ADRESS commands are aborted. The address value returns to the origin when the
SET MAX ADDRESS EXT command is executed using the address value
returned by the READ NATIVE MAX ADDRESS command.
At command issuance (I/O registers setting contents)
1F7 (CM)
H
1F6 (DH)
H
1F5 (CH)
H
1F4 (CL)
H
1F3 (SN)
H
1F2 (SC)
H
1F1 (FR)
H
C141-E195-02EN
1 1 1 1
x L x DV
Max. cylinder [MSB]/Max. LBA
Max. cylinder [LSB]/Max. LBA
Max. sector/Max. LBA [LSB]
xx
xx
5.3 Host Commands
1 0 0 1
Max head/LBA [MSB]
VV
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