HI-3596, HI-3597, HI-3598, HI-3599
comparedꢀtoꢀtheꢀfirstꢀ(MSB)ꢀbitꢀofꢀeachꢀSPIꢀ8-bitꢀdataꢀ
fieldꢀfromꢀSPIꢀinstructionꢀn1ꢀhex,ꢀwhereꢀ“n”ꢀisꢀtheꢀchan-
Line Receiver Input Pins
The HI-3598 has two sets of Line Receiver input pins,
RINA/B and RINA/B-40. Only one pair may be used
to connect to the ARINC 429 bus. THE RINA/B pins
may be connected directly to the ARINC 429 bus. The
RINA/B-40ꢀpinsꢀrequireꢀanꢀexternalꢀ40KΩꢀresistorꢀtoꢀbeꢀ
added in series with each ARINC input without affect-
ing the ARINC input thresholds. This option is especially
useful in applications where lightning protection circuitry
is also required.
nel number 1-8 hex.
IfꢀaꢀchannelꢀControlꢀRegisterꢀCR2ꢀbitꢀequalsꢀ”0,”ꢀtheꢀcor-
responding receiver recognizes all label values as valid,
as shown in Table 9.
Reading the Label Memory
Theꢀcontentsꢀofꢀeachꢀchannel’sꢀLabelꢀMemoryꢀmayꢀbeꢀ
read via the SPI interface using instruction n2 hex where
“n”ꢀequalsꢀtheꢀchannelꢀnumberꢀ1-8ꢀhex,ꢀasꢀdescribedꢀinꢀ
Table 2.
When using the RINA/B-40 pins, each side of the ARINC
busꢀmustꢀbeꢀconnectedꢀthroughꢀaꢀ40KΩꢀseriesꢀresistorꢀ
in order for the chip to detect the correct ARINC levels.
The typical 10V differential signal is translated and input
to a window comparator and latch. The comparator lev-
elsꢀareꢀsetꢀsoꢀthatꢀwithꢀtheꢀexternalꢀ40KΩꢀresistors,ꢀtheyꢀ
are just below the standard 6.5V minimum ARINC data
threshold and just above the standard 2.5V maximum
ARINC null threshold.
Digital Transmit Function
The Transmit Register can be used as a digital transmit-
ter by connecting the TX1 and TX0 pins to an external
ARINC 429 line driver such as the HI-8570 or HI-8571
(except HI-3599).
When using HI-3596, HI-3597 or HI-3599, only one set
of ARINC 429 receive inputs are provided for each chan-
nel. The standard HI-3596, HI-3597 and HI-3599 use the
direct-connection RINA / RINB pins. The HI-3596-40,
HI-3597-40 and HI-3599-40 devices use the RINA-40 /
RINB-40ꢀpinsꢀandꢀrequireꢀexternalꢀ40KΩꢀseriesꢀresis-
tors. See the Ordering Information table for complete
part number options.
Loopback Self-Test
The HI-359x devices may use the Transmit Register
toꢀexecuteꢀuser-definedꢀself-testꢀsequencesꢀ(loopbackꢀ
test) for each receiver. This feature may be individually
enabled for each receiver by resetting Control Register
CR5ꢀbitꢀtoꢀ“0”.ꢀꢀAꢀ32-bitꢀtestꢀwordꢀisꢀloadedꢀtoꢀtheꢀTrans-
mit Register using SPI instructions n8 hex (for ARINC
429 high-speed data rate) or n9 hex (for ARINC 429 low
speed). Upon completion of the instruction, the word is
shifted out of the register and routed to all receivers.
If self-test mode is enabled and the receive channel
is set to the correct speed, each channel will receive
the test word as if it came from an external ARINC 429
bus.ꢀIfꢀloopbackꢀisꢀnotꢀenabled,ꢀtheꢀchannelꢀignoresꢀtheꢀ
self-test word and continues to respond to the external
ARINC 429 bus (Note: In the case of HI-3597, RIN1A
and RIN1B pins are not available). In all cases, the serial
test word may be observed at the TX1 and TX0 pins
(except HI-3599), as shown in Table 10.
Please refer to the Holt AN-300 Application Note for
additional information and recommendations on light-
ning protection of Holt line drivers and line receivers.
Master Reset (MR)
Assertion of Master Reset (MR) causes immediate ter-
mination of data reception. The eight Receive FIFOs
areꢀcleared.ꢀStatusꢀRegisterꢀFIFOꢀflagsꢀandꢀFIFOꢀstatusꢀ
output signals are also cleared. Master Reset does not
affect the eight channel Control Registers. Master Reset
may be asserted using the MR input pin (HI-3596 and
HI-3598 only) or by executing SPI instruction n7 hex.
NOTE:ꢀTheꢀfirstꢀbitꢀshiftedꢀintoꢀtheꢀSelfꢀTestꢀregisterꢀwillꢀ
beꢀtheꢀfirstꢀbitꢀsentꢀtoꢀtheꢀreceiversꢀandꢀtheꢀTX1ꢀandꢀTX0ꢀ
pins. In ARINC 429 protocol, this bit is the LSB.
An individual receive channel can be reset by setting
itsꢀcorrespondingꢀControlꢀRegisterꢀCR3ꢀbitꢀtoꢀ“1”.ꢀThisꢀ
clearsꢀ theꢀ channel’sꢀ receiverꢀ logicꢀ andꢀ Receiveꢀ FIFOꢀ
andꢀdisablesꢀtheꢀreceiverꢀuntilꢀCR3ꢀisꢀresetꢀtoꢀ“0”.ꢀForꢀ
applications requiring less than eight channels, unused
receivers should be held in reset by setting the corre-
sponding Control Register CR3 bits.
Table 10. Test Outputs
TX1
0
TX0
0
ARINC 429 State
NULL
1
0
ONE
0
1
ZERO
HOLT INTEGRATED CIRCUITS
9