HI-8282
time as EN , the byte will also be placed into the transmitter FIFO.
SEL is then taken high and EN is strobed again to place the upper
byte of the data word on the data bus. By strobing PL2 at the same
time as EN , the second byte will also be placed into the FIFO. The
data word is now ready to be transmitted according to the parity
programmed into the control word register.
REPEATER OPERATION
The repeater mode of operation allows a data word that has been
received by the HI-8282 to be placed directly into its FIFO for
transmission. After a 32-bit word has been shifted into the receiver
shift register, the D/R flag will go low. A logic "0" is placed on the SEL
line and EN is strobed. This is the same procedure as for normal
receiver operation and it places the lower byte (16) of the data word
In normal operation, either byte of a received data word may be read
from the receiver latches first by use of SEL input. During repeater
operation however, the lower byte of the data word must be read
first. This is necessary because, as the data is be ing read, it is also
being loaded into the FIFO and the transmitter FIFO is always
By strobing PL1 at the same
loaded with the lower byte of the data word first.
on the data bus.
429DO
429DO
ARINC BIT
DATA
NULL
DATA
DATA
NULL
NULL
BIT 31
BIT 1
NEXT WORD
WORD GAP
BIT 32
BIT 30
DATA BUS
VALID
tCWSET
tCWHLD
CWSTR
tCWSTR
tEND/R
tEN
tD/R
tSELEN
tSELEN
tENSEL
tENSEL
tENEN
tDATAEN
tD/REN
tDATAEN
BYTE 1 VALID
BYTE 2 VALID
DATA BUS
tENDATA
tENDATA
HOLT INTEGRATED CIRCUITS
4-34
HOLTIC [ HOLT INTEGRATED CIRCUITS ]
