HD-15530 Datasheet, PDF (6/12 Pages) Intersil Corporation – CMOS Manchester Encoder-Decoder

HD-15530
MIL-STD-1553
The 1553 standard defines a time division multiplexed data
bus for application within aircraft. The bus is defined to be
bipolar, and encoded in a Manchester II format, so no DC
component appears on the bus. This allows transformer
coupling and excellent isolation among systems and their
environment.
The HD-15530 supports the full bipolar configuration,
assuming a bus driver configuration similar to that in Figure
1. Bipolar inputs from the bus, like Figure 2, are also accom-
modated.
The signaling format in MlL-STD-1553 is specified on the
assumption that the network of 32 or fewer terminals are
controlled by a central control unit by means of Command
Words. Terminals respond with Status Words. Each word is
preceded by a synchronizing pulse, and followed by parity
bit, occupying a total of 20µs. The word formats are shown in
Figure 4. The special abbreviations are as follows:
P
Parity, which is defined to be odd, taken across all 17
bits.
R/T Receive on logical zero, transmit on ONE.
ME Message Error if logical 1.
TF Terminal Flat, if set, calls for controller to request
self-test data.
The paragraphs above are intended only to suggest the
content of MlL-STD-1553, and do not completely describe its
bus requirements, timing or protocols.
BUS
“1”
“0”
FIGURE 6. SIMPLIFIED MIL-STD-1553 DRIVER
+
-
“1”
“1” REF
“0” REF
-
+
“0”
BUS
FIGURE 7. SIMPLIFIED MIL-STD-1553 RECEIVER
COMMAND
SYNC
DATA
SYNC
BIT
PERIOD
BIT
PERIOD
BIT
PERIOD
LOGICAL ONE DATA
LOGICAL ZERO DATA
FIGURE 8. MIL-STD-1553 CHARACTER FORMATS
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
COMMAND WORD (FROM CONTROLLER TO TERMINAL)
SYNC
5
1
5
5
1
TERMINAL
ADDRESS
SUB ADDRESS
/MODE
DATA WORD
COUNT
P
R/T
DATA WORD (SENT EITHER DIRECTION)
16
1
SYNC
CONTROL WORD
P
STATUS WORD (FROM TERMINAL TO CONTROLLER)
SYNC
5
TERMINAL
ADDRESS
1
9
11
CODE FOR FAILURE MODES TF P
ME
FIGURE 9. MIL-STD-1553 WORD FORMATS
NOTE: This page is a summary of MIL-STD-1553 and is not intended to describe the operation of the HD-15530.
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