
SMSC DS – FDC37N958FR
Page 42
Rev. 09/01/99
Table 22 - Status Register 2
BIT NO.
7
6
SYMBOL
NAME
DESCRIPTION
Unused. This bit is always "0".
Any one of the following:
1.
Read Data command - the FDC encountered a
deleted data address mark.
2.
Read Deleted Data command - the FDC
encountered a data address mark.
The FDC detected a CRC error in the data field.
CM
Control Mark
5
DD
Data Error in
Data Field
Wrong Cylinder
4
WC
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.
3
2
1
BC
Bad Cylinder
0
MD
Missing Data
Address Mark
Table 23 - Status Register 3
BIT NO.
7
6
5
4
3
2
1,0
SYMBOL
NAME
DESCRIPTION
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 HDSEL pin.
Indicates the status of the nDS1, nDS0 pins.
WP
Write Protected
T0
Track 0
HD
DS1,0
Head Address
Drive Select
FDC RESET
There are three sources of system reset on the
FDC: the nRESET_OUT bit of the 8051’s Output
enable
Register
(which
RESET_OUT/nRESET_OUT
FDC37N958FR); a reset generated via a bit in the
DOR; and a reset generated via a bit in the DSR.
At VCC2 power on, a VCC2 Power On Reset
initializes the FDC. All resets take the FDC out of
the power down state.
All operations are terminated upon a RESET, and
the Floppy Disk Controller enters an idle state. A
reset while a disk write is in progress will corrupt
the data and CRC.
controls
pins
the
the
of
On exiting the reset state, various internal
registers are cleared, including the Configure
command information, and the Floppy Disk
Controller waits for a new command. Drive polling
will start unless disabled by a new Configure
command.