HI-3200, HI-3201
ARINC 429 Immediate Transmit Option
The Host CPU may instruct the HI-3200 to transmit an
ARINC 429 message immediately using a special SPI
command. The SPI command selects the transmit
channel and provides the four bytes of data to be sent as
a 32-bit ARINC 429 message.
If the transmit sequencer for the selected channel is
active, then the new message is transmitted as soon as
the current message has been sent. The sequencer then
resumes operation at the next location in the queue.
Both the RUN input and the Master Control Register
A429TX bit must be high to enable any ARINC 429
transmission.
If the transmit channel’s sequencer is not running (ATCR
bit RUN/STOP = “0”), or the sequencer is waiting for the
repetition rate counter to rollover, then the new ARINC
429 message is transmitted without delay.
Table 1 lists the host CPU SPI instruction format.
HOLT INTEGRATED CIRCUITS
31
HOLTIC [ HOLT INTEGRATED CIRCUITS ]
