DP8473N NSC [National Semiconductor], DP8473N Datasheet - Page 15

• Manufacturer Part Number: DP8473N
• Description: DP8473 Floppy Disk Controller PLUS-2
• Manufacturer: NSC [National Semiconductor]

Command Description Table
SCAN HIGH OR EQUAL
Command Phase
Result Phase
SEEK
Command Phase
Note 2
RECALIBRATE
Command Phase
SENSE INTERRUPT
Command Phase
Result Phase
Note 2
IPS
MT MFM SK
X
0
0
0
0
MSB of Track
MSN PTN
X
X
0
0
0
0
Present Track Number (PTN)
End of Track Sector Number
Number of Bytes per Sector
Intersector Gap Length
Drive Head Number
New Track Number
X
0
X
0
0
0
Status Register 0
Status Register 1
Status Register 2
Status Register 0
Sector Step Size
Sector Number
Sector Number
Track Number
Track Number
Head Number
Bytes Sector
1
X
0
X
0
0
0
1
X
1
X
0
0
0
1
0
HD DR1 DR0
1
1
X
0
1
0
0
0
DR1 DR0
DR1 DR0
0
1
0
1
0
0
1
1
0
1
0
0
SENSE DRIVE STATUS
Command Phase
Result Phase
SPECIFY
Command Phase
MODE
Command Phase
Note 3
SET TRACK
Command Phase
Result Phase
Note 3
INVALID COMMAND
Command Phase
Result Phase
TMR IAF IPS
Step Rate Time (N1)
X
0
0
0
0
1
0
0
0
(Continued)
R W
X
0
0
0
0
1
0
0
Motor On Time (N3)
Status Register 0
New Track Number
X
0
0
0
0
0
0
1
1
Status Register 3
Invalid Op Codes
WLD
0
X
0
0
0
0
0
0
1
Value
15
LW
Motor Off Time (N2)
0
X
0
0
0
0
0
0
Head Settle
MSB DR1 DR0
HD DR1 DR0
RG
PR
1
0
0
0
0
0
1
0
1
0
0
0
DMA
ETR
PU
0
1
1
0
1
Note 1 The IPS bit is only enabled if the IPS bit
in the mode command is set Otherwise this bit is
a don’t care
Note 2 Shaded byte only written or read if the
extended track range mode is enabled in the
Mode Command (ET)
Note 3 These commands are additional en-
hanced commands
Note Mnemonic Definitions
X
MFM
MSN PTN
Track Number
MT
IPS
bit is a don’t care unless the IPS bit in the mode
command is set )
SK
HD
DRn
TMR
IAF
LW PR
ETR
WLD
RG
DSKCHG pin for the Data Separator
PU
output on the PUMP PREN pin
MSB
least significant byte of the track is read 1
MSB
R W
read (Read
e
e
e
e
e
e
e
e
DON’T CARE
e
e
e
e
e
e
e
Skip Sector
Enables Charge Pump PUMP signal to be
Multi-Track
Implied Seek (In individual commands this
Head Number
Index Address Field
e
Drive to Select (encoded)
Extended Track Range
Enables the Read Gate Input on the
Motor Head Timer Mode
Wildcard in Scan
Data Encoding Scheme
Selects whether the most significant or
Selects whether the track is written or
Low Power Mode
e
e
0 Write
Most Significant Nibble Present
e
e
1
1)
e