CT2566 Aeroflex Circuit Technology, CT2566 Datasheet - Page 11

• Manufacturer Part Number: CT2566
• Description: CT2566 MIL-STD-1553 to Microprocessor Interface Unit
• Manufacturer: Aeroflex Circuit Technology

BC Operation
the Configuration Register to logic "0". This can be done
by writing directly to the register or by issuing a
MSTRCLR or RESET command. Note that a RESET
will also clear the Interrupt Mask Register.
shown in Table 3 and follows the steps in Figure 11, BC
Initialization. The CPU loads the data blocks with 1553
messages (See Figure 12). The first word of each data
block must contain the Control Word (shown in Figure
13) for the message. The starting addresses of the data
blocks are placed in the fourth word of the Descriptor
Stack in the order the messages are to be transmitted
(i.e. the address of the first message is loaded into the
fourth location of the Stack, the address of the second
message is placed into the eighth location, etc). Once
the data blocks and the Descriptor Stack have been
initialized, the CPU loads the current area message
count with the number of messages to transfer (load in
1’s complement).
The BC mode is selected by setting the two MSBs of
BC Initialization.
For BC operation, the user initializes the RAM as
Aeroflex Circuit Technology
BROADCAST
BROADCAST
BROADCAST
COMMAND
COMMAND
COMMAND
CONTROL
(NO DATA)
(NO DATA)
BACK BY
LOOPED
CT2565
WORD
DATA WORD
DATA WORD
DATA WORD
DATA WORD
COMMAND
CONTROL
DATA BLOCK
RECEIVE
BACK BY
RECEIVE
LOOPED
STATUS
CT2566
WORD
RECEIVE
LAST
LAST
1
2
Figure 12 – BC Message Data Block Formats
DATA BLOCK
DATA WORD
DATA WORD
DATA WORD
COMMAND
COMMAND
TRANSMIT
TRANSMIT
TRANSMIT
CONTROL
RECEIVED
BACK BY
LOOPED
STATUS
CT2565
WORD
LAST
1
2
TERMINAL TO
DATA BLOCK
FROM XMTR
DATA WORD
DATA WORD
1 RECEIVED
2 RECEIVED
LAST DATA
COMMAND
COMMAND
COMMAND
TRANSMIT
TRANSMIT
RECEIVED
RECEIVER
TERMINAL
CONTROL
RECEIVE
BACK BY
LOOPED
WORD 2
REMOTE
REMOTE
WORD 1
STATUS
STATUS
CT2565
WORD
WORD
FROM
11
DATA BLOCK
MODE CODE
DATA WORD
DATA WORD
COMMAND
WITH DATA
CONTROL
0100
0101
0104
0105
0108-013F
0140-017F
0180-01BF
01C0-01FF
0F00-0FFF
0000-00FF
BACK BY
RECEIVE
LOOPED
FORMAT
STATUS
CT2565
WORD
MODE
WORD
HEX ADDRESS
•
•
Table 3 - Typical BC Memory Map
DATA BLOCK
MODE CODE
DATA WORD
WITH DATA
COMMAND
COMMAND
TRANSMIT
RECEIVED
CONTROL
BACK BY
LOOPED
FORMAT
STATUS
CT2565
WORD
WORD
MODE
MODE
User Defined Areas
SCDCT2566 REV B 8/10/99 Plainview NY [phone]
(4K memory)]
Fixed Areas
MODE CODE
COMMAND
COMMAND
CONTROL
WITHOUT
BACK BY
LOOPED
STATUS
CT2565
WORD
WORD
MODE
MODE
DATA
Stack Pointer A
Message Count A
Stack Pointer B
Message Count B
Not Used
Data Block 1
Data Block 2
Data Block 3
Descriptor Stack A
Descriptor Stack B
•
•
FUNCTION
BROADCAST
BROADCAST
DATA WORD
DATA WORD
DATA WORD
DATA WORD
COMMAND
COMMAND
WITH DATA
BACK BY
LOOPED
CT2565
LAST
1
2