DP8473N NSC [National Semiconductor], DP8473N Datasheet - Page 2

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

General Description
the data rate 83 ns 125 ns 208 ns 250 ns for data rates of
1 0M 500k 300k 250 kb s respectively
Specifically to support the PC-AT and PC-XT design the
Floppy Disk Controller PLUS-2 includes address decode for
the A0–A2 address lines the motor drive select register
data rate register for selecting 250 300 500 kb s Disk
Changed status dual speed spindle motor control low write
current and DMA interrupt sharing logic The controller also
supports direct connection to the P bus via internal 12 mA
buffers The controller also can be connected directly to the
disk drive via internal open drain high drive outputs and
Schmitt inputs
In addition to this logic the DP8473 includes many features
to ease design of higher performance drives and future con-
troller upgrades These include 1 0 Mb s data rate extend-
ed track range to 4096 Implied seeking working Scan Com-
mands motor control timing both standard IBM formats as
well as Sony 3 5 (ISO) formats and other enhancements
Block Diagram
Note 1 The MTR2 MTR3 DR2 and DR3 are not available on the 48 pin DIP (DP8473N J) versions
Note 2 See Figure 4 for filter description
Note 3 Total transistor count is 29 700 (approx)
(Continued)
FIGURE 1 DP8473 Functional Block Diagram
2
This device is available in a 52 pin Plastic Chip Carrier and
in a 48 pin Dual-In-Line package
Table of Contents
General Description
Pin Description
Functional Description
Register Description
Result Phase Register Description
Processor Software Interface
Command Description Table
Command Descriptions
DC and AC Characteristics
TL F 9384– 3