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 NAME
RECALIBRATE
READ SECTOR(S)
WRITE SECTOR(S)
WRITE VERIFY
READ VERIFY SECTOR(S)
SEEK
EXECUTE DEVICE DIAGNOSTIC
INITIALIZE DEVICE PARAMETERS 1
DOWNLOAD MICROCODE
STANDBY IMMEDIATE
IDLE IMMEDIATE
UNLOAD IMMEDIATE
STANDBY
C141-E254
COMMAND CODE (Bit)
7
6
5
4
3
0
0
0
1
X
0
0
1
0
0
0
0
1
1
0
0
0
1
1
1
0
1
0
0
0
0
1
1
1
X
1
0
0
1
0
0
0
1
0
1
0
0
1
0
1
0
0
1
0
1
1
1
0
0
1
0
0
1
0
1
1
1
0
0
1
0
0
1
0
1
1
1
0
0
1
0
0
1
0
1
1
1
0
0
5.3 Host Commands
PARAMETER USED
2
1
0
FR
SC
X
X
X
N
N
0
0
R
N
Y
0
0
R
N
Y
1
0
0
N
Y
0
0
R
N
Y
X
X
X
N
N
0
0
0
N
N
0
0
1
N
Y
0
1
0
Y
Y
1
0
0
N
N
0
0
0
1
0
1
Y
N
0
0
1
1
0
1
Y
N
0
0
1
1
1
0
N
Y
0
1
0
SN CY DH
N
N
D
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
Y
Y
N
D
N
N
D
Y
Y
D
Y
Y
D
N
N
D
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