Pin
No. Name Function
Status Register
2
Not used. This bit
is
always
0
(low).
D6
CM (Control During execution of the Read Data or
Scan command, if the FDC encounters
a sector which contains
a
deleted data
address mark, this flag is set.
Mark)
~
D,
DD
(Data
If
the FDC detects
a
CRC error in the
data field then this flag is set.
Error in
Data Field)
D, WC (Wrong
This bit is related to the ND bit, and
when the contents
of
C(3) on the
medium is different from that stored in
the IDR, this flag is set.
Cylinder)
D,
SH (Scan During execution of the Scan
Equal Hit)
command, if the condition of “equal”
is satisfied, this flag is set.
D, SN (Scan During execution of the Scan
Not
Satisfied)
command, if the
FDC
cannot find a
sector on the cylinder which meets the
condition, then this flag is set.
D, BC (Bad
Cylinder)
This bit is related to the ND bit, and
when the contents of C on the medium
is different from that stored in the
IDR and the contents of C is FFH,
then this flag is set.
Do
MD (Missing When data is read from the medium,
Address
Mark in
Data Field)
if the FDC cannot find
a
data address
mark or deleted data address mark,
then this flag is set.
Pin
No. Name
Function
Status Register
3
D,
FT
This bit
is
used to indicate the status
(Fault)
of the fault signal from the
FDD.
D,
WP (Write
This bit is used to indicate the status
of the write protected signal from the
FDD.
Protected)
D,
RY
This bit is used to indicate the status
(Ready)
of the ready signal from the
FDD.
D,
TO
This bit is used to indicate the status
(Track
0)
of the track
0
signal from the
FDD.
D,
TS This bit is used to indicate the status
of the two-side signal from the FDD.
(Two-Side)
D,
HD (Head
This bit is used to indicate the status
of the side select signal to the
FDD.
This bit is used to indicate the status
of the unit select
1
signal to the
FDD.
Address)
D,
US, (Unit
Select
1)
Do
US, (Unit
This bit is used to indicate the status
of the unit select
0
signal to the
FDD.
Select
0)
Notes:
CRC
=
Cyclic Redundancy Check
IDR=Internal Data Register
Cylinder (C) is described more fully in the
Command Symbol Description.
F-24
To Next Page
Loading...
