5.3 Host Commands
(38) SET MAX (X’F9’)
| SET MAX Features Register Values | |
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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 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.
