5962G8957701ZC View Datasheet(PDF) - Aeroflex UTMC
Part Name
Description
Manufacturer
5962G8957701ZC Datasheet PDF : 61 Pages
| |||
6.1.2 Message Status Word
Each message the BCRTM transacts has a corresponding
Message Status Word, which is pointed to by the Message
Status List Pointer of the Descriptor. This word allows the
host CPU to evaluate the message’s validity, determine the
word count, and calculate the approximate time frame in
which the message was transacted (figures 7 and 8).
15 14 13 12
87
0
WORD COUNT
TIME TAG
MESSAGE ERROR
MESSAGE WAS BROADCASTED
SUBSYSTEM FAIL INPUT WAS
ASSERTED DURING THIS MESSAGE
Figure 7. Message Status Word
DATA LIST
MESSAGE
#1
MESSAGE
#2
MESSAGE
#3
MESSAGE
#4
MESSAGE
#5
MESSAGE STATUS
LIST POINTER
DATA LIST
POINTER
(FROM RT DESCRIPTOR)
MESSAGE STATUS WORD
LIST
#1
#2
#3
#4
#5
Figure 8. Remote Terminal Data and Message Status List
Message Status Word Definition
Bit
Number
Description
BIT 15
BIT 14
BIT 13
BITs 12-8
BITs 7-0
Subsystem Failed. Indicates SSYSF was asserted before the Message Status Word transfer to memory. This
bit is also set when the user sets bit 13 of Register 10.
Broadcast Message. Indicates that the corresponding message was received in the broadcast mode.
Message Error. Indicates a message is invalid due to improper synchronization, bit count, word count, or
Manchester error.
Word Count. Indicates the number of words in the message and reflects the Word Count field in the command
word. Should the message contain a different number of words than the Word Count field, the Message Error
flag is triggered. If there are too many words, they are withheld from RAM. If the actual word count is less than
it should be, the Message Error bit in the 1553 status word is set.
Time Tag. The BCRTM writes the internally generated Time Tag to this location after message completion.
The resolution is 64µs. (See Register 13). If the timer reads 2, it indicates the message was completed 128 to
191µs after the timer started.
BCRTM-25
|
|
Share Link: 