FIFO

LOAD

CONTROL

SEL

EN

CONTROL

BIT

/

R/W

CONTROL

32 TO 16 DRIVER

32 BIT SHIFT REGISTER

TO PINS

CONTROLBITS

CR0, CR14

CLOCK

OPTION

CLOCK

CLK

BIT

COUNTER

AND

END OF

SEQUENCE

PARITY

CHECK

32ND

BIT

DATA

BIT CLOCK

WORD GAP

WORD GAP

TIMER

BIT CLOCK

END

START

SEQUENCE

CONTROL

ERROR

CLOCK

ERROR

DETECTION

SHIFT REGISTER

SHIFT REGISTER

NULL

ZEROS

SHIFT REGISTER

ONES

EOS

FIGURE 2.

RECEIVER BLOCK DIAGRAM

LABEL /

DECODE

COMPARE

16x8

LABEL

MEMORY

32X32

FIFO

D/R

FF

MUX

CONTROL

BITS

HF

FUNCTIONAL DESCRIPTION (cont.)

0

X

0

X

Load FIFO

1

No

0

X

Ignore data

1

Yes

0

X

Load FIFO

0

X

1

No

Ignore data

0

X

1

Yes

Load FIFO

1

Yes

1

No

Ignore data

1

No

1

Yes

Ignore data

1

No

1

No

Ignore data

1

Yes

1

Yes

Load FIFO

CR2(3) ARINC word CR6(9)

ARINC word

FIFO

matches

bits 9,10

label

match

CR7,8 (10,11)

RECEIVER PARITY

The receiver parity circuit counts Ones received, including the

parity bit. If the result is odd, then "0" will appear in the 32nd bit.

RETRIEVING DATA

Once 32 valid bits are recognized, the receiver logic generates an

End of Sequence (EOS). Depending upon the state of control

register bits CR2-CR11, the received ARINC 32-bit word is then

checked for correct decoding and label matching before being

loaded into the 32 x 32 receive FIFO. ARINC words which do not

meet the necessary 9th and 10th ARINC bit or label matching are

ignored and are not loaded into the receive FIFO. The following

table describes this operation.

HOLT INTEGRATED CIRCUITS

5

HI-3584