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5.3 Host Commands
5.3 Host Commands
The host system issues a command to the device by writing necessary parameters in
related fields 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 5.5 lists the supported commands, command code and the related fields to
be written necessary parameters at command execution.
Table 5.5 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-E280 5-27