hi-6131pqtf QuickLogic Corp, hi-6131pqtf Datasheet - Page 200

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

Such messages do not update CA, so the next message
overwrites the same buffer space.
For transmit commands, the device begins transmis-
sion of data retrieving the first data word stored at ad-
dress CA+2. (Reminder: addresses CA and CA+1 are
reserved for the Message Information and Time-Tag
words.) When message processing is complete, the
device writes the Message Information and Time-Tag
words into the buffer. If no errors were detected, the
device updates descriptor CA register. If the next ad-
dress location (last retrieved data word +1) is less than
or equal to EA, CA is updated to (last retrieved address
+1). If the next address location (last retrieved data word
+1) is greater than EA, the transmit data buffer is empty;
CA is updated to the SA value. If the descriptor Control
Word IXEQZ bit is asserted (and if the Interrupt Enable
Register IXEQZ bit is asserted) the device indicates
“transmit buffer empty” by asserting the INTMES inter-
rupt output.
Circular Buffer Mode 1 does not support NOTICE2 seg-
regation of broadcast data, even when the NOTICE2 bit
equals 1 in Configuration Register 1. Data from broad-
HOLT INTEGRATED CIRCUITS
HI-6130, HI-6131
200
cast and non-broadcast receive commands is stored in
the same buffer. The BCAST bit in the Message Infor-
mation Word reflects broadcast or non-broadcast status
for each stored message. If broadcast messages are
not expected during data block transmission, the host
can illegalize broadcast commands for the subaddress.
Broadcast illegalization can be done either permanently,
or only when data block transmission is scheduled.
For transmit subaddresses using Circular Buffer Mode
1, occurrences of broadcast-transmit commands to
RT31 do not result in bus transmission. However these
messages update the Message Information Word ad-
dressed by the Current Address (CA) pointer (and fol-
lowing Time-Tag Word) but afterwards, the CA pointer
remains unchanged. The next transmit command to the
same subaddress, whether broadcast or not, overwrites
the Message Information and Time-Tag Word locations
written by the previous broadcast transmit command.