BU-61582 데이터 시트보기 (PDF) - Unspecified
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BU-61582 Datasheet PDF : 48 Pages
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BC MESSAGE BLOCK FORMATS AND BC CONTROL
WORD
In BC mode, the BU-61582 supports all MIL-STD-1553 message
formats. For each 1553 message format, the BU-61582 man-
dates a specific sequence of words within the BC Message
Block. This includes locations for the Control, Command and
(transmitted) Data Words that are to be read from RAM by the
BC-to-RT Transfer
Control Word
Receive Command Word
Data Word #1
Data Word #2
.
.
.
Last Data Word
Last Data Word Looped Back
Status Received
RT-to-BC Transfer
Control Word
Transmit Command Word
Transmit Command Looped Back
Status Received
Data Word #1
Data Word #2
.
.
.
Last Data Word
RT-to-RT Transfer
Control Word
Receive Command
Transmit Command
Transmit Command
Looped Back
Tx RT Status Word
Data #1
Data #2
.
.
.
Last Data
Rx RT Status Word
Mode Code;
No Data
Control Word
Mode Command
Mode Command
Looped Back
Status Received
Tx Mode Code;
With Data
Control Word
Tx Mode Command
Mode Command
Looped Back
Status Received
Data Word
BC protocol logic. In addition, subsequent contiguous locations
must be allocated for storage of received Loopback, RT Status
and Data Words. FIGURE 4 illustrates the organization of the BC
message blocks for the various MIL-STD-1553 message for-
mats. Note that for all of the message formats, the BC Control
Word is located in the first location of the message block.
The BC Control Word is not transmitted on the 1553 bus.
Instead, it contains bits that select the active bus and message
format, enable off-line self-test, masking of Status Word bits,
enable retries and interrupts, and specify MIL-STD-1553A or -
1553B error handling. The bit mapping and definitions of the BC
Control Word are illustrated in TABLE 10.
The BC Control Word is followed by the Command Word to be
transmitted, and subsequently by a second Command Word (for
an RT-to-RT transfer), followed by Data Words to be transmitted
(for Receive commands). The location after the last word to be
transmitted is reserved for the Loopback Word. The loopback
Word is an on-line self-test feature. The subsequent locations
after the Loopback Word are reserved for received Status Words
and Data Words (for Transmit commands).
AUTOMATIC RETRIES
The BU-61582 BC implements automatic message retries. When
enabled, retries will occur, following response timeout or format
error conditions. As additional options, retries may be enabled
when the Message Error Status Word bit is set by a 1553A RT or
following a “Status Set” condition. For a failed message, either
one or two message retries will occur, and the bus channel
(same or alternate) is independently programmable for the first
and second retry attempts. Retries may be enabled or disabled
on an individual message basis.
Rx Mode Code;
With Data
Control Word
Rx Mode Command
Data Word
Data Word Looped
Back
Status Received
Broadcast
Control Word
Broadcast Command
Data #1
Data #2
.
.
.
Last Data
Last Data Status
Word
RT-to-RTs (Broadcast)
Transfer
Control Word
Rx Broadcast Command
Tx Command
Tx Command
Looped Back
Tx RT Status Word
Data #1
Data #2
.
.
.
Last Data
Broadcast Mode Code;
No Data
Control Word
Broadcast Mode Command
Broadcast Mode Command
Looped Back
Broadcast Mode Code;
With Data
Control Word
Broadcast Mode Command
Data Word
Data Word Looped Back
FIGURE 4. BC MESSAGE BLOCK FORMATS
BC INTERRUPTS
BC interrupts may be enabled by the Interrupt Mask Register for
Stack Rollover, Retry, End-of-Message (global), End-of-
Message (in conjunction with the BC Control Word for individual
messages), response timeout, message error, end of BC frame,
and Status Set conditions. The definition of “Status Set” is pro-
grammable on an individual message basis by means of the BC
Control Word. This allows for masking (“care/don’t care”) for the
individual RT Status Word bits.
REMOTE TERMINAL (RT) ARCHITECTURE
The RT protocol design of the BU-61582 represents DDC’s fifth
generation implementation of a 1553 RT. One of the salient fea-
tures of the SP’ACE’s RT architecture is its true multiprotocol
functionality. This includes programmable options for support of
MIL-STD-1553A, the various McAir protocols, and MIL-STD-
1553B Notice 2. The BU-61582 RT response time is 2 to 5 µs
dead time (4 to 7 µs per 1553B), providing compliance to all the
1553 protocols. Additional multiprotocol features of the BU-
61582 include options for full software control of RT Status and
Built-in-Test (BIT) words. Alternatively, for 1553B applications,
Data Device Corporation
www.ddc-web.com
15
BU-61582
M-08/04-0
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