User`s guide

3.5 ISA Bus Devices
3.5.1 Combination Controller
The EB164 uses the National Semiconductor PC87312 as the combination
controller chip. (See Figure 3–3.) It is packaged in a 100-pin PQFP
configuration. The chip provides the following ISA peripheral functions:
• Integrated drive electronics (IDE) controller—Provides a complete IDE
interface. Signal buffers are provided on the EB164. The interface is
brought out to a standard 40-pin header. A ribbon cable connects the
header to one or two IDE drives. An ‘‘IDE Drive Active’’ indicator can be
connected to header J2 (see Figure 2–4).
• Diskette controller—Software compatible to the Intel PC8477 (contains
a superset of the Intel DP8473 and NEC PD765) and the Intel N82077
FDC functions. The onchip analog data separator requires no external
filter components and supports the 4MB drive format and other standard
diskette drives used with 5.25-inch and 3.5-inch media. FDC data and
control lines are brought out to a standard 34-pin connector. A ribbon cable
interfaces the connector to one or two diskette drives.
• Serial ports—Two universal asynchronous receiver–transmitters (UARTs)
with full modem control, compatible with NS16450 or PC16550 devices,
are brought out to separate onboard, 10-pin connectors. The lines can be
brought out through 25-pin female D-sub connectors on the bulkhead of a
standard PC enclosure.
• Parallel port—The bidirectional parallel port is brought out to an onboard
26-pin connector, J33. It can be brought out through a 25-pin female D-sub
connector on the bulkhead of a standard PC enclosure.
An onboard 9154-10 clock generator chip supplies a 24-MHz reference clock for
the diskette data separator and serial ports.
Refer to National Semiconductor document PC87311/PC87312 (SuperI/O™
II/III) Floppy Disk Controller with Dual UARTs, Parallel Port, and IDE
Interface for additional information.
3–10 Functional Description