2.4 Mode Code and Subaddress
The SµΜΜIT provides subaddress and mode code decoding
that meets MIL-STD-1553B requirements. In addition, the
device has automatic internal illegal command decoding for
reserved MIL-STD-1553B mode codes. Table 3 shows the
SRT’s response to all possible mode code combinations.
T/R
Mode Code
0
00000-01111
0
10000
0
10001
0
10010
0
10011
0
10100
0
10101
0
10110-11111
1
00000
1
00001
1
00010
1
00011
1
00100
Table 3. Mode Code Descriptions
Function
Operation
Undefined (w/o data)
1. Command word stored
2. Status word transmitted
Undefined (with data)
1. Command word stored
2. Data word stored
3. Status word transmitted
Synchronize (with data)
1. Command word stored
2. Data word stored
3. Time-Tag counter loaded with data word value
4. Status word transmitted
Undefined
1. Command word stored
2. Data word stored
3. Status word transmitted
Undefined
1. Command word stored
2. Data word stored
3. Status word transmitted
Selected Transmitter
Shutdown
1. Command word stored
2. Data word stored
3. Status word transmitted
Override Selected
Transmitter Shutdown
1. Command word stored
2. Data word stored
3. Status word transmitted
Reserved
1. Command word stored
2. Data word stored
3. Status word transmitted
Dynamic Bus Control
1. Command word stored
2. Dynamic Bus Acceptance bit set in outgoing
status word if enabled in the Control Register
3. Status word transmitted
Synchronize
1. Command word stored
2. Time-Tag counter reset to 0000 (hex)
3. Status word transmitted
Transmit Status Word
1. Command word stored
2. Last status word transmitted
3. Status word cleared after master reset
Note: SRT updates status word if illegalized.
Initiate Self-Test
1. Command word stored
2. Status word transmitted
3. BIT initiated
4. TF bit set if BITF bit asserted
Transmitter Shutdown
1. Command word stored
2. Status word transmitted
3. Alternate bus disabled
SµMMIT FAMILY
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