CT2566 Datasheet, PDF (15/37 Pages) Aeroflex Circuit Technology – CT2566 MIL-STD-1553 to Microprocessor Interface Unit

4. Stores the Command Word received.
5. Reads a Block address from the Look-Up Table
using the T/R bit and the subaddress from the
Command Word; transfers the Block address into
the address register. Data words are transferred
to/from memory by the associated 1553 interface
unit using the address register.
RTU EOM Sequence
At the end of a 1553 message (valid or invalid) the
CT2566 received an EOM pulse and then performs the
following:
1. Updates the Block Status Word.
2. Updates the Time Stage if used.
3. Increments the Stack Pointer by four.
4. Generates an Error Interrupt if enabled.
1553 COMMAND WORD
RECEIVED
READ STACK POINTER
UPDATE DESCRIPTOR STACK
BLOCK STATUS WORD, TIME
TAG AND COMMAND WORD
READ LOOK-UP TABLE USING
T/R SUBADDRESS CURRENT
AREA BIT B/A
START
ISSUE RESET COMMAND
INITIALIZE STACK POINTER
SET UP LOOK-UP TABLE(S)
DATA BLOCK ASSIGNMENTS
SET UP DATA BLOCKS
SET CONFIGURATION
REGISTER TO RTU MODE
INITIALIZE INTERRUPT
MASK REGISTER
WAIT FOR 1553 COMMAND
Figure 15
RTU Initialization (under user control)
TRANSFER DATA TO/FROM
1553 INTERFACE DEVICE
MESSAGE COMPLETE
NO
?
YES
UPDATE BLOCK STATUS WORD
AND TIME TAG
INCREMENT STACK POINTER
BY FOUR
GENERATE EOM INTERRUPT AND
ERROR INTERRUPT IF ERROR
CONDITION DETECTED
EXIT
Figure 17 – RTU Sequence of Operation
(under CT2566 control)
RECEIVED COMMAND WORD
RTU
WORD
ADDR T/R SUBADD COUNT
XXXXX 0 00000 XXXXX
XXXXX 0 00001 XXXXX
XXXXX 0 00010 XXXXX
LOOK-UP TABLE
}^{USER DEFINED 0140}
USER DEFINED 0141
USER DEFINED 0142
64
LOCATIONS
XXXXX 1 11110 XXXXX
XXXXX 1 11111 XXXXX
USER DEFINED ^017E
USER DEFINED _017F
Figure 16 – RTU Look-up Table
Aeroflex Circuit Technology
15
SCDCT2566 REV B 8/10/99 Plainview NY [phone]