PC87311A Datasheet, PDF (1/78 Pages) National Semiconductor (TI) – PC87311A/PC87312 (SuperI/OTM II/III) Floppy Disk Controller with Dual UARTs, Parallel Port, and IDE Interface

October 1993
PC87311A PC87312 (SuperI O^TM II III)
Floppy Disk Controller with Dual UARTs
Parallel Port and IDE Interface
General Description
The PC87311A 12 incorporates a floppy disk controller
(FDC) two full function UARTs a bidirectional parallel port
and IDE interface control logic in one chip The PC87311A
includes standard AT XT address decoding for on-chip
functions and a Configuration Register offering a single
chip solution to the most commonly used IBM PC
PC-XT and PC-AT peripherals The PC87312 includes
standard AT address decoding for on-chip functions and a
Configuration Register set offering a single chip solution to
the most commonly used ISA EISA and Micro Channel pe-
ripherals
The on-chip FDC is software compatible to the PC8477
which contains a superset of the DP8473 and NEC mPD765
and the N82077 floppy disk controller functions The on-
chip analog data separator requires no external compo-
nents and supports the 4 Mb drive format as well as the
other standard floppy drives used with 5 25 and 3 5 me-
dia
In the PC87311A the UARTs are equivalent to two
INS8250N-Bs or NS16450s The bidirectional parallel port
maintains complete compatibility with the IBM PC XT and
AT In the PC87312 the UARTs are equivalent to two
NS16450s or PC16550s The bidirectional parallel port
maintains complete compatibility with the ISA EISA and Mi-
cro Channel parallel ports
The IDE control logic provides a complete IDE interface ex-
cept for the signal buffers The Configuration Registers con-
sist of three byte-wide registers An Index and a Data Regis-
ter which can be relocated within the ISA I O address space
access the Configuration Registers
Features
Y _{100% compatible with IBM PC XT and AT architec-}
tures (PC87311A) or ISA EISA and Micro Channel ar-
chitectures (PC87312)
Y _FDC
Software compatible with the DP8473 the 765A and
the N82077
16-byte FIFO (default disabled)
Burst and Non-Burst modes
Perpendicular Recording drive support
High performance internal analog data separator (no
external filter components required)
Low power CMOS with power down mode
Y _UARTs
Software compatible with the INS8250N-B and the
NS16450 (PC87311A) or PC16550A and PC16450
(PC87312)
Y _{Parallel Port}
Bidirectional under either software or hardware
control
Compatible with all IBM PC XT and AT architectures
(PC87311A) or all ISA EISA and Micro Channel ar-
chitectures (PC87312)
Back Voltage protection circuit against damage
caused when printer is powered up
Y _{IDE Control Logic}
Provides a complete IDE interface except for option-
al buffers
Y _{Address Decoder}
Provides selection of all primary and secondary ISA
addresses including COM 1 – 4
Y _{100-pin PQFP package}
The PC87311A and PC87312 are pin compatible
Block Diagram
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SuperI OTM is a trademark of National Semiconductor Corporation
IBM PC PC-AT PC-XT and PS 2 are registered trademarks of International Business Machines Corporation
C1995 National Semiconductor Corporation TL F 11362
TL F 11362 – 1
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