FUJITSU DISK DRIVES MHM215OAT User Manual

Page 120

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5.3 Host Commands

C141-E104-02EN

5-43

Multiword DMA transfer mode X

00100 000 (X’20’: Mode 0)

00100 001 (X’21’: Mode 1)

00100 010 (X’22’: Mode 2)

Ultra DMA transfer mode X

01000 000 (X’40’: Mode 0)

01000 001 (X’41’: Mode 1)

01000 010 (X’42’: Mode 2)

01000 011 (X’43’: Mode 3)

01000 100 (X’44’: Mode 4)

The host writes the Sector Count register with the desired power management
level and executes this command with the Features register X’05’, and then
Advanced Power Management is enabled.

Level

Sector Count register

Power management without standby
Power management with standby
Reserved

80h-FEh

01h-7Fh

FFh, 00h

(15) SET MULTIPLE MODE (X’C6’)

This command enables the device to perform the READ MULTIPLE and
WRITE MULTIPLE commands. The block count (number of sectors in a
block) for these commands are also specified by the SET MULTIPLE MODE
command.

The number of sectors per block is written into the Sector Count register. The
IDD supports 2, 4, 8, 16 and 32 (sectors) as the block counts.

Upon receipt of this command, the device sets the BSY bit of the Status register
and checks the contents of the Sector Count register. If the contents of the Sector
Count register is valid and is a supported block count, the value is stored for all
subsequent READ MULTIPLE and WRITE MULTIPLE commands. Execution
of these commands is then enabled. If the value of the Sector Count register is not
a supported block count, an ABORTED COMMAND error is posted and the
READ MULTIPLE and WRITE MULTIPLE commands are disabled.

If the contents of the Sector Count register is 0, 1 when the SET MULTIPLE
MODE command is issued, the READ MULTIPLE and WRITE MULTIPLE
commands are disabled.

When the SET MULTIPLE MODE command operation is completed, the device
clears the BSY bit and generates an interrupt.

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