LPC47S457-NC SMSC [SMSC Corporation], LPC47S457-NC Datasheet - Page 40

• Manufacturer Part Number: LPC47S457-NC
• Description: Advanced I/O with X-Bus Interface
• Manufacturer: SMSC [SMSC Corporation]

RESET
There are three sources of system reset on the FDC: the PCI_RESET# pin, a reset generated via a bit in the DOR, and
a reset generated via a bit in the DSR. At power on, a Power On Reset initializes the FDC. All resets take the FDC out
of the power down state.
All operations are terminated upon a PCI_RESET#, and the FDC enters an idle state. A reset while a disk write is in
progress will corrupt the data and CRC.
On exiting the reset state, various internal registers are cleared, including the Configure command information, and the
FDC waits for a new command. Drive polling will start unless disabled by a new Configure command.
PCI_RESET# Pin (Hardware Reset)
The PCI_RESET# pin is a global reset and clears all registers except those programmed by the Specify command.
The DOR reset bit is enabled and must be cleared by the host to exit the reset state.
DOR Reset vs. DSR Reset (Software Reset)
These two resets are functionally the same. Both will reset the FDC core, which affects drive status information and the
FIFO circuits. The DSR reset clears itself automatically while the DOR reset requires the host to manually clear it. DOR
reset has precedence over the DSR reset. The DOR reset is set automatically upon a pin reset. The user must
manually clear this reset bit in the DOR to exit the reset state.
SMSC DS – LPC47S45x
BIT NO.
BIT NO.
1,0
7
6
5
4
3
2
1
0
7
6
5
4
3
2
CM
DD
WC
BC
MD
WP
T0
HD
DS1,0
SYMBOL
SYMBOL
Control Mark
Data Error in
Data Field
Wrong
Cylinder
Bad Cylinder
Missing Data
Address Mark
Write
Protected
Track 0
Head Address Indicates the status of the HDSEL pin.
Drive Select
NAME
NAME
Table 14 − Status Register 2
Table 15 − Status Register 3
DATASHEET
Page 40 of 259
Unused. This bit is always "0".
Any one of the following:
Read Data command - the FDC encountered a deleted
Read Deleted Data command - the FDC encountered a
The FDC detected a CRC error in the data field.
The track address from the sector ID field is different
from the track address maintained inside the FDC.
Unused. This bit is always "0".
Unused. This bit is always "0".
The track address from the sector ID field is different
from the track address maintained inside the FDC and is
equal to FF hex, which indicates a bad track with a hard
error according to the IBM soft-sectored format.
The FDC cannot detect a data address mark or a
deleted data address mark.
Unused. This bit is always "0".
Indicates the status of the WP pin.
Unused. This bit is always "1".
Indicates the status of the TRK0 pin.
Unused. This bit is always "1".
Indicates the status of the DS1, DS0 pins.
data address mark.
data address mark.
DESCRIPTION
DESCRIPTION
Rev. 07/09/2001