Table 14 – Status Register 1
NAME DESCRIPTION
BIT NO.
SYMBOL
7
EN
End of
The FDC tried to access a sector beyond the final sector
of the track (255D). Will be set if TC is not issued after
Read or Write Data command.
Cylinder
6
5
Unused. This bit is always "0".
DE
OR
Data Error
The FDC detected a CRC error in either the ID field or
the data field of a sector.
4
Overrun/
Underrun
Becomes set if the FDC does not receive CPU or DMA
service within the required time interval, resulting in data
overrun or underrun.
3
2
Unused. This bit is always "0".
Any one of the following:
ND
No Data
1. Read Data, Read Deleted Data command - the FDC
did not find the specified sector.
2. Read ID command - the FDC cannot read the ID field
without an error.
3. Read A Track command - the FDC cannot find the
proper sector sequence.
Not Writeable WP pin became a "1" while the FDC is executing a Write
Data, Write Deleted Data, or Format A Track command.
1
0
NW
MA
Missing
Any one of the following:
Address Mark
1. The FDC did not detect an ID address mark at the
specified track after encountering the index pulse
from the nINDEX pin twice.
2. The FDC cannot detect a data address mark or a
deleted data address mark on the specified track.
Table 15 – Status Register 2
NAME
Unused. This bit is always "0".
Control Mark Any one of the following:
BIT NO.
SYMBOL
DESCRIPTION
7
6
CM
Read Data command - the FDC encountered a deleted
data address mark.
Read Deleted Data command - the FDC encountered a
data address mark.
Data Error in The FDC detected a CRC error in the data field.
Data Field
5
4
DD
WC
Wrong
The track address from the sector ID field is different
Cylinder
from the track address maintained inside the FDC.
3
2
1
Unused. This bit is always "0".
Unused. This bit is always "0".
Bad Cylinder 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.
BC
0
MD
Missing Data The FDC cannot detect a data address mark or a
Address Mark deleted data address mark.
SMSC DS – LPC47M14X
Page 38
Rev. 03/19/2001
SMSC [ SMSC CORPORATION ]
