HI-3210
Current Sequence number
TRANSMIT SEQUENCE POINTERS 0 -3
(Address 0x802C - 0x802F)
7
6
5
4
3
2
1
0
LSB
MSB
The transmit sequence pointer is set to zero on Master
This continues until the programmed sequence is
complete. The sequence pointer is then reset to the
beginning of the descriptor table and program execution
begins as soon the channel repetition rate counter time
elapses.
Reset. Once the Control Register RUN / STOP bit goes
high, sequence execution begins at sequence count
zero. After the first word is sent, the pointer is
incremented by one descriptor (counts descriptor
frames).
Channel Repetition Period
REPETITION RATE REGISTER
(Address 0x801C - 0x801F)
7
6
5
4
3
2
1
0
LSB
MSB
The Repetition rate register value defines the time
interval between successive starts of the programmed
transmit sequence for each ARINC 429 transmit channel.
The value is set in binary, with the LSB representing 10
ms. Repetition rate time periods may therefore be set
from 0 ms to 2.55 seconds
When the Repetition Rate counter is programmed to zero
(default), the transmit sequence shall execute one time
only. A zero - to - one transition of the RUN/STOP bit will
cause the transmit sequence to start. One-time execution
of the sequencer is useful when transmitting ARINC 429
words directly from the host CPU. One or more
immediate-mode descriptors can be written into the
sequence table, transmitted, and then refreshed for the
next cycle.
If the repetition rate is shorter than the minimum time
needed to transmit all ARINC 429 words in the sequence
(but not zero), the transmit sequence will begin again
immediately if the Control Register SKIP bit is a zero. If
the SKIP bit is a one, the sequencer will wait until the
next rollover of the Repetition Rate Counter before
starting a new cycle.
HOLT INTEGRATED CIRCUITS
22
HOLTIC [ HOLT INTEGRATED CIRCUITS ]
