5.3 Host Commands
(36) SET MAX (X’F9’)
SET MAX Features Register Values
Value | Command |
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00h | Obsolete |
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01h | SET MAX SET PASSWORD |
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02h | SET MAX LOCK |
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03h | SET MAX UNLOCK |
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04h | SET MAX FREEZE LOCK |
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05h - FFh | Reserved |
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•SET MAX ADDRESS
A successful READ NATIVE MAX ADDRESS command shall immediately precede a SET MAX ADDRESS command.
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 saves the maximum address specified in the DH, CH, CL and SN field then, reports the status to the host.
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 field bit 0, VV (Value Volatile), is 1, the value set by this command is held even after power on. When the VV bit is 0, the value set by this command becomes invalid when the power is turned on, and the maximum address returns to the value most lately set when VV bit = 1. (When the command with VV=1 has not issued before, the maximum address returns to the default value.)
When the READ NATIVE MAX ADDRESS command has been issued immediately preceding this command, this command operates normally as the SET MAX ADDRESS command. Otherwise, this command operates as one of the SET MAX subcommands depending on the value in the Features field. The subcommands are explained below.
After power on, 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 ID Not Found error.
When the SET MAX ADDRESS EXT command is executed, SET MAX ADDRESS command is 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.
