
5.3 Host Commands
5.3 Host Commands
The host system issues a command to the device by writing necessary parameters
in related fileds in the shadow block registers and writing a command code in the
Command field of the shadow block registers.
The device can accept the command when the BSY bit is 0 (the device is not in the
busy status).
The host system can halt the uncompleted command execution only at execution
of COMRESET or software reset.
When the BSY bit is 1 or the DRQ bit is 1 (the device is requesting the PIO data
transfer) and the host system writes to the command field of the shadow block
register, the correct device operation is not guaranteed.
5.3.1 Command code and parameters
Table 5.6 lists the supported commands, command code and the related fields to
be written necessary parameters at command execution.
Table 5.6 Command code and parameters (1/3)
COMMAND CODE (Bit)
PARAMETER USED
COMMAND NAME
7 6 5 4 3 2 1 0 FR SC
SN
CY DH
RECALIBRATE
0 0 0 1 X X X X N N N N D
READ
SECTOR(S)
0 0 1 0 0 0 0 R N Y Y Y Y
WRITE
SECTOR(S)
0 0 1 1 0 0 0 R N Y Y Y Y
WRITE
VERIFY
0 0 1 1 1 1 0 0 N Y Y Y Y
READ
VERIFY
SECTOR(S)
0 1 0 0 0 0 0 R N Y Y Y Y
SEEK
0 1 1 1 X X X X N N Y Y Y
EXECUTE
DEVICE
DIAGNOSTIC 1 0 0 1 0 0 0 0 N N N N N
INITIALIZE
DEVICE
PARAMETERS 1 0 0 1 0 0 0 1 N Y N N Y
DOWNLOAD
MICROCODE
1 0 0 1 0 0 1 0 Y Y Y N D
STANDBY IMMEDIATE
1
1
0
1
0
1
1
0
0
0
1
0
0
0
0
0
N N N N D
IDLE IMMEDIATE
1
1
0
1
0
1
1
0
0
0
1
0
0
0
1
1
Y N Y Y D
UNLOAD IMMEDIATE
1
1
0
1
0
1
1
0
0
0
1
0
0
0
1
1
Y N Y Y D
STANDBY
1
1
0
1
0
1
1
0
0
0
1
0
1
1
0
0
N Y N N D
C141-E249
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Содержание MHW2040BS
Страница 1: ...C141 E249 01EN MHW2120BS MHW2100BS MHW2080BS MHW2060BS MHW2040BS DISK DRIVES PRODUCT MANUAL ...
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Страница 18: ...Contents 6 5 1 Cache operation 6 20 Glossary GL 1 Acronyms and Abbreviations AB 1 Index IN 1 xiv C141 E249 ...
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Страница 86: ...Interface Figure 5 2 Example of the circuit for driving Ready LED 5 12 C141 E249 ...
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