HI-8581

GENERAL DESCRIPTION

The HI-8581 device from Holt Integrated Circuits isa silicon

gate CMOS device for interfacinga 16-bit parallel data bus

directly to the ARINC 429 serial bus. The device provides

two receivers, an independent transmitter and line driver

capability ina single package. The receiver input circuitry

and logic are designed to meet the ARINC 429

specifications for loading, level detection, timing, and

protocol. The transmitter section provides the ARINC 429

communication protocol and the line driver circuits provide

the ARINC 429 output levels.

The 16-bit parallel data bus exchanges the32-bit ARINC

data word in two steps when either loading the transmitter

or interrogating the receivers. The data bus interfaces with

CMOS and TTL.

Timing of all the circuitry begins with the master clock input,

CLK.

For ARINC 429 applications, the master clock

frequency is1 MHz.

Each independent receiver monitors the data stream witha

sampling rate 10 times the data rate. The sampling rate is

software selectable at either 1MHz or 125KHz. The results

ofa parity check are available as the 32nd ARINC bit. The

HI-8581 examines the null and data timings and will reject

erroneous patterns. For example, witha 125 KHz clock

selection, the data frequency must be between 10.4 KHz

and 15.6 KHz.

The transmitter hasa First In, First Out (FIFO) memory to

store8 ARINC words for transmission. The data rate of the

transmitter is software selectable by dividing the master

clock, CLK, by either 10 or 80. The master clock is used to

set the timing of the ARINC transmission within the required

resolution.

APPLICATIONS

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Avionics data communication

Serial to parallel conversion

Parallel to serial conversion

FEATURES

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ARINC specification 429 compatible

Direct receiver and transmitter interface to

ARINC bus ina single device.

16-Bit parallel data bus.

Timing control 10 times the data rate

Selectable data clocks

Receiver error rejection per ARINC

specification 429

Automatic transmitter data timing

Self test mode

Parity functions

Low power

Industrial& full military temperature ranges

June 2001

33-

32- N/C

31- V+

30- TXB(OUT)

29- TXA(OUT)

28- V-

27- GND

26- TX/R

25-

24-

23-

ENTX

BD00

PL2

PL1

429DI2(B) -1

-2

-3

SEL -4

-5

-6

BD15 -7

BD14 -8

BD13 -9

BD12- 10

BD11- 11

D/R1

D/R2

EN1

EN2

HI-8581PQI

&

HI-8581PQT

HOLT INTEGRATED CIRCUITS

1

(DS8581 Rev. A)

06/01

(See page 13 for additional pin configurations)