hd1-15530-8 Intersil Corporation, hd1-15530-8 Datasheet - Page 6

• Manufacturer Part Number: hd1-15530-8
• Description: Cmos Manchester Encoder-decoder
• Manufacturer: Intersil Corporation

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
NOTE: This page is a summary of MIL-STD-1553 and is not intended to describe the operation of the HD-15530.
COMMAND
“1”
“0”
FIGURE 8. MIL-STD-1553 CHARACTER FORMATS
SYNC
SYNC
LOGICAL ZERO DATA
FIGURE 6. SIMPLIFIED MIL-STD-1553 DRIVER
DATA
LOGICAL ONE DATA
PERIOD
BIT
PERIOD
BIT
PERIOD
BIT
BUS
HD-15530
147
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
R/T
ME
TF
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.
COMMAND WORD (FROM CONTROLLER TO TERMINAL)
DATA WORD (SENT EITHER DIRECTION)
STATUS WORD (FROM TERMINAL TO CONTROLLER)
0
SYNC
SYNC
SYNC
1
BUS
FIGURE 7. SIMPLIFIED MIL-STD-1553 RECEIVER
2
Parity, which is defined to be odd, taken across all 17
bits.
Receive on logical zero, transmit on ONE.
Message Error if logical 1.
Terminal Flat, if set, calls for controller to request
self-test data.
FIGURE 9. MIL-STD-1553 WORD FORMATS
3
TERMINAL
TERMINAL
ADDRESS
ADDRESS
4
5
5
5
6
7
ME
R/T
1
1
8
CONTROL WORD
9
SUB ADDRESS
CODE FOR FAILURE MODES
10
/MODE
16
11
5
12
13
9
14
+
+
-
-
“1” REF
“0” REF
DATA WORD
15
COUNT
16
5
17
“1”
“0”
18
TF
1
19
P
P
P
1
1
1