GM82C803CN Datasheet, PDF (32/84 Pages) List of Unclassifed Manufacturers – 2.88 MB FDC/ Dual UARTs with FIFO/PIO(EPP/ ECP)/ IDE Interface/ S-IR/ PnP

Table 4-11. Status Register 0 (ST0)
Bit
Symbol
Name
7,6
IC
Interrupt Code
5
SE
4
EC
3
2
HS
1,0
DS1,0
Seek End
Equipment Check
Unused
Head Select
Drive Select 1,0
Table 4-12. Status Register 1 (ST1)
Bit
Symbol
Name
7
EN
End of cylinder
6
5
DE
4
OR
3
2
ND
Unused
Data Error
Overrun
Unused
No Data
1
NW
Not Writable
0
MA
Missing Address
Mark
GM82C803CN
Function
00 : Normal termination of command was completed
and properly executed.
01 : Abnormal termination of command. Execution
of command was started but was not successfully
completed.
10 : Invalid command issue. Command which was is-
sued was never started.
11 : Internal drive ready status changed state during
the drive polling mode.
Only occurs after a reset.
When the FDC completes the Seek command, this flag is set to 1.
If Track 0 signal fails to occur after 255 step pulses (Recalibrate
command), then this flag is set to 1.
Always 0.
Indicates the HDSEL (pin# : 11) status.
Indicates the logical drive status selected.
00 : Drive 0, 01 : Drive1
10 : Drive 2, 11 : Drive3
Function
The FDC tried to access a sector beyond the final sector of a
cylinder. It will be set if TC is not issued after Read or Write Data
command.
Always 0.
When the FDC detects a CRC error in either ID field or data field,
this flag is 1.
If the FDC is serviced by host during data transfers within a
certain timer interval, this flag is 1.
Always 0.
Any one of the following :
1. During Read (Deleted) Data command, FDC do
not find the specified sector.
2. During Read ID command , FDC cannot read the
ID field without an error.
3. During Read a Track command, the FDC can not
find the proper sector sequence.
During Write (Deleted) Data or Format a Track command, if FDC
detects a WRTPRT (pin#:14) signal from the FDD, then this flag
is 1.
Any one of the following :
1. The FDC do not detect an ID address mark at the
specified track after encountering the index hole
pulse twice.
2. The FDC can not detect a data address mark or a
deleted data address mark on the specified track.