HI-6130_16 Datasheet, PDF (97/296 Pages) Holt Integrated Circuits – 3.3V BC / MT / RT Multi-Terminal Device

HI-6130, HI-6131
Message
Word
Word Name Word Function when using 16-bit time tag
Block
Word 1
Message
Sixteen bit message time stamp.
Time Stamp
Bits 15 ~ 0 ^{Word 0 is the first word in the Command Buffer entry for each message.}
Word 0
Block Status ^{Message Block Status Word, defined in Section 12.2.}
Word
Word 0 is the first word in the Command Buffer entry for each message.
When MT Configuration Register bits 1-0 equal 11, the Simple Message Monitor operates with 48-bit Time Tag
resolution. Each MIL-STD-1553 message adds an 8-word entry in the Circular Command Buffer. This is summarized
in Table 10. The expanded message block accommodates two additional Time Tag words, a Message Length word
and a Response Time word not found when using 16-bit Time tag resolution.
Table 10.  Message Block in Circular Command Buffer for SMT Monitor using 48-bit Time Tag
Message
Word
Word Name Word Function when using 16-bit time tag
Block
Word 7
Message
Command
Word
Message Command Word.
The MIL-STD-1553 Command Word that initiated the message.
For an RT-RT message, Receive Command Word 1 is stored here; Transmit Command
Word 2 is the first stored word in the Message Data Block.
Word 6
Data Block
Pointer
Starting address in the Data Buffer for the corresponding message data block.
Word 5
The Message Length Word indicates the total number of bytes of the 1553 message
including all command words and status words. The range is 2 to 72 bytes,
Message
corresponding to 1 to 36 16-bit words stored.
Length Word _{Note: Since the Message Command Word is stored within the Message Block itself, the}
(bytes)
number of bytes to read from the Message Data Block should be reduced by 2 bytes.
That is, the number of bytes to read from the Message Data Block = Message Length
Word − 2.
The Response Time Word contains two 8-bit fields:
Word 4
Response
Time Word
• Bits 15 ~ 8 contains GAP2
• Bits 7 ~ 0 contains GAP1
All GAP values are measured from mid-parity zero crossing of the preceding word, to
the mid-sync zero crossing of the Status Word (the gap “dead time” interval plus 2 µs).
Time resolution is 100 ns per LSB, so the maximum indicated gap time for GAP1 or
GAP2 is 25.5 µs.
For RT-RT messages, the GAP1 byte indicates transmit RT response time, and the
GAP2 byte indicates received RT response time.
For all other messages, the GAP1 byte indicates the only RT response time, and the
GAP2 byte reads 0x00.
HOLT INTEGRATED CIRCUITS
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