SIGNAL

SECTION

FUNCTION

DESCRIPTION

VALID WORD

DECODER

OUTPUT

A high output signals the receipt of a valid word

ENCODER SHIFT CLOCK

ENCODER

OUTPUT

Shifts data into the encoder on a low to high transition

TAKE DATA

DECODER

OUTPUT

Output is high during receipt of data after identification of a Sync

Pulse and two valid Manchester data bits.

SERIAL DATA OUT

DECODER

OUTPUT

Received Data output in NRZ format

DECODER CLOCK

DECODER

INPUT

12x the data rate. Clock for the transition finder and synchronizer,

which generates the internal clock for the remainder of the decoder

BIPOLAR ZERO IN

DECODER

INPUT

A high input indicates the 1553 bus is in its negative state.

This pin must be held high when the Unipolar input is used

BIPOLAR ONE IN

DECODER

INPUT

A high input indicates the 1553 bus is in the positive state.

This pin must be held low when the Unipolar input is used

UNIPOLAR DATA IN

DECODER

INPUT

Input for unipolar data to the transition finder. Must be held low when

Not in use

DECODER SHIFT CLOCK

DECODER

OUTPUT

Provides the DECODER CLOCK divided by 12, synchronized by the

recovered serial data

COMMAND /

SYNC

DECODER

OUTPUT

A high on this pin occurs during the output of decoded data which

was preceded by a Command (or Status) synchronizing character. A

low output indicates a Data synchronizing character

DECODER RESET

DECODER

INPUT

A high applied to this pin during a DECODER SHIFT CLOCK rising

edge resets the bit counter

GND

BOTH

POWER

0V supply

MASTER RESET

BOTH

INPUT

A high on this pin clears the 2:1 counters in both Encoder and

Decoder and resets the divide-by-6 circuit

6 OUT

ENCODER

OUTPUT

Provides ENCODER CLOCK divided by 6

ENCODER

OUTPUT

An active low output intended to drive the zero or negative sense of

a MIL-STD-1553 Line Driver

ENCODER

INPUT

A low inhibits the

and

by

forcing them to inactive high states

ENCODER

OUTPUT

An active low output intended to drive the one or positive sense on a

MIL-STD-1553 Line Driver

SERIAL DATA IN

ENCODER

INPUT

Accepts serial data at the rate of the ENCODER SHIFT CLOCK

ENCODER ENABLE

ENCODER

INPUT

A high on this pin initiates the encode cycle. (Subject to the

preceeding cycle being complete)

SYNC SELECT

ENCODER

INPUT

Actuates a Command Sync for an input high and a Data Sync for a

low

SEND DATA

ENCODER

OUTPUT

An active high output which enables the external source of serial

Data

SEND CLOCK IN

ENCODER

INPUT

Clock input at 2 times the Data rate, usually driven by

6 OUT

ENCODER CLOCK

ENCODER

INPUT

Input to the divide by 6 circuit. Normal frequency is Data rate x12

VDD

BOTH

POWER

3.0 V to 5.5 V power supply pin

DATA

BIPOLAR ZERO OUT

OUTPUT INHIBIT

BIPOLAR ZERO OUT

BIPOLAR ONE OUT

BIPOLAR ONE OUT

¸

¸

PIN DESCRIPTIONS

HOLT INTEGRATED CIRCUITS

2

HI-15530