READ ID
DATA BUS
D5 D4 D3
PHASE
Command
R/W D7
D6
MFM
0
D2
0
D1
1
D0
0
REMARKS
Commands
W
W
0
0
0
0
0
0
1
0
HDS DS1 DS0
Execution
Result
The first correct ID
information
on
the
Cylinder is stored in
Data Register
R
ST0
Status information after
Command execution.
Disk status after the
Command has
completed
R
R
R
R
R
R
ST1
ST2
C
H
R
N
PERPENDICULAR MODE
DATA BUS
PHASE
Command
R/W
W
D7
0
OW
D6 D5 D4 D3 D2
D1
1
D0
0
WGATE
REMARKS
Command Codes
0
0
0
1
0
0
D3 D2 D1 D0
GAP
INVALID CODES
DATA BUS
R/W D7 D6 D5 D4 D3 D2 D1 D0
PHASE
REMARKS
Command
W
Invalid Codes
Invalid
Command
Codes
(NoOp - FDC goes into Stand-
by State)
Result
R
ST0
ST0 = 80H
LOCK
DATA BUS
PHASE
Command
Result
R/W
W
R
D7
LOCK
0
D6 D5
D4
1
LOCK
D3 D2 D1 D0
REMARKS
Command Codes
0
0
0
0
0
0
1
0
0
0
0
0
SC is returned if the last command that was issued was the Format command. EOT is returned if the last command was
a Read or Write.
Note: These bits are used internally only. They are not reflected in the Drive Select pins. It is the user's
responsibility to maintain correspondence between these bits and the Drive Select pins (DOR).
SMSC DS – LPC47M14X
Page 49
Rev. 03/19/2001
SMSC [ SMSC CORPORATION ]
