hi-6131pqtf QuickLogic Corp, hi-6131pqtf Datasheet - Page 77

• Manufacturer Part Number: hi-6131pqtf
• Description: Mil-std-1553 / Mil-std-1760 3.3v Bc / Mt / Rt Multi-terminal Device
• Manufacturer: QuickLogic Corp

Bit No.
6
5
Mnemonic
BSYNDV
(continued)
BCGTE
R/W
R/W
R/W
Reset
0
0
HOLT INTEGRATED CIRCUITS
Function
A busy RT is one that is functional, but cannot send or receive data
when commanded by the Bus Controller. An RT that is busy sets
the Busy bit in its Status Word responses. In response to transmit
commands, the busy terminal has no words to transmit, so only the
Status Word is transmitted. In the case of the “transmit vector word” and
transmit BIT word” mode code commands, even if the data is available
to the terminal, it is prohibited to send the data word if the Busy bit is set
in the Status Word.
There is just one defined situation in which an RT transmits Busy
status with one (and only one) data word: An RT receives a “transmit
last command” mode command (MC18 decimal). When the previous
valid command for the RT had Busy status, the RT responds with last
message status condition (with Busy bit set) and one data word, the
previous Command Word.
BC Message Gap Timer Enable.
If bit 5 is logic 0, the BC does not add delay between 1553 messages.
Message timing is paced by the time required for the BC to complete
message post processing. In this case, the minimum inter-message gap
will be used, with a bus “dead time” of approximately 6 to 9µs.
If bit 5 is logic 1, the BC Message Timer is enabled. The “Time to Next
Message” value from the Message Control Block is decremented at
1µs rate. When the count decrements from 1 to 0, the next message
starts. If the specified message gap time is less than the time needed
for the current message, the next message will start immediately after
completion of the current message. In this case, the minimum inter-
message gap will be used, with a bus “dead time” of approximately 6 to
9µs. This allows the BC to implement minor frame cycle times without
host processor intervention.
If BSYMASK = 0 in
•
Wrong number of
BC Control Word
HI-6130, HI-6131
data words
Condition
If the RT responds to a transmit command with Busy status and
the wrong number of data words (but not 0), here is the message
result:
77
(MSTATSET) bit = 1.
Block Status Word Condition Code Register
Masked Status Set
(STATSET) bit = 1.
Format Error (FE)
Word Count Error
(LE) bit = 1.
Status Set
bit = 1
Bad Message (BADMSG)
Format Error (FMTERR)
(MSTATSET) bit = 1.
Masked Status Set
----------
bit = 1
bit = 1