hi-6131pqtf QuickLogic Corp, hi-6131pqtf Datasheet - Page 211

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

21.4. Standard Mode Command
Data buffer options for mode commands differ from
buffer options for subaddress commands. Mode com-
mands can use ping-pong buffering or indexed buffer-
ing. When mode commands use indexed buffers, “single
message mode” (INDX = 0) is recommended. When us-
ing indexed or ping-pong buffers for mode commands:
21.5. Simplified Mode Command
Mode commands have a buffer alternative that is un-
available for subaddress commands. The SMCP bit in
Configuration Register 1 selects Simplified Mode Com-
mand Processing, a global option applying to all mode
commands. When the SMCP bit is high, mode com-
mand descriptor blocks (in the Descriptor Table) do not
contain data pointers to reserved buffers elsewhere in
the shared RAM. Instead, each 4-word descriptor block
itself contains the message information word, the time-
tag word and the data from the most recent occurrence
of each mode command:
•
•
•
For mode commands without associated data word
(mode codes 0-15 decimal), only the Message In-
formation and Time-Tag words are updated in the
mode command’s assigned data buffer in RAM.
For mode commands 16-31 (decimal) that receive
a data word, indexed and ping-pong buffer meth-
ods copy the received mode data word to the mode
command’s assigned data buffer in shared RAM,
after the message is transacted. The Message In-
formation and Time-Tag words are also updated.
For most mode commands 16-31 (decimal) that
transmit a data word, the device reads the data
word for transmit from the buffer location assigned
in the Descriptor Table. Exceptions occur for MC18
“transmit last command” and for MC19 “transmit
BIT word.” The MC18 data word is automatically
provided by the device, based on recent command
transactions. The MC19 data word comes from
register 0x14 or 0x15, depending on the state of
the ALTBITW option in Configuration Register 2.
For both MC18 and MC19, the transmitted data
word is automatically recorded in the mode com-
mand’s assigned data buffer in RAM, after mes-
sage completion. The Message Information and
Time-Tag words are also updated.
Processing
Processing
HOLT INTEGRATED CIRCUITS
HI-6130, HI-6131
211
Descriptor Word 1 contains the receive or transmit mode
command Control Word. When SMCP is used, just two
Control Word bits are used: DBAC (descriptor block ac-
cessed) and BCAST (broadcast).
When SMCP is enabled, the host need not initialize
the mode code command segments in the Descriptor
Table. When Simplified Mode Command Processing is
selected, the host does not write Descriptor Words 2-3
in the Descriptor Table entries for mode commands. For
mode code values 0 to 15 decimal, the Descriptor Word
4 serves no function because these mode codes do not
have an associated data word. For transmit mode code
values 16 to 31, the host may initialize Descriptor Word
4. The default transmit value is 0x0000. Mode com-
mand MC16 “transmit vector word” is one of the three
defined mode commands that transmit a data word:
MC16, MC18 and MC19. Its Descriptor Word 4 should
be initialized if a value other than 0x0000 is needed.
MC18 and MC19 are discussed below.
Descriptor Word 1 Mode Command Control Word
Descriptor Word 2 Message Information Word
Descriptor Word 3 Time-Tag Word
Descriptor Word 4 Mode Data Word
•
•
•
For mode commands without associated data
word (mode codes 0-15 decimal), Simplified Mode
Command Processing updates the Message Infor-
mation and Time-Tag words in Descriptor Words 2
and 3, and Descriptor Word 1 (bits 9,11). For these
commands, SMCP does not update Descriptor
Word 4, which may be non-zero if written earlier
by the host.
For receive mode commands 16-31 (decimal) that
receive a data word, Simplified Mode Command
Processing copies the received mode data word to
Descriptor Word 4. The Message Information and
Time-Tag words in Descriptor Words 2 and 3, and
Descriptor Word 1 (bits 9, 11) are also updated.
For most transmit mode codes 16-31 (decimal), the
device reads the data word for transmission from
each command’s Descriptor Word 4. Exceptions
occur for MC18 “transmit last command” and for
MC19 “transmit built-in test word”. The MC18 data
word is automatically provided, based on the last
command transacted. The MC19 data word comes
from register 0x14 or 0x15, depending on the state
of the ALTBITW option in Configuration Register 2.
For MC18 and MC19, the transmitted data value
is automatically copied to the mode command’s
Descriptor Word 4 after message completion.
The Message Information and Time-Tag words in