HI-6121PQMF HOLTIC [Holt Integrated Circuits], HI-6121PQMF Datasheet - Page 49

• Manufacturer Part Number: HI-6121PQMF
• Description: MIL-STD-1553 Remote Terminal ICs
• Manufacturer: HOLTIC [Holt Integrated Circuits]

MESSAGE DATA BUFFERS, Cont.
11
10
9
8
7
6
5
REGARDING MODE COMMAND MESSAGE INFORMATION WORDS
Mode command data structures in shared RAM are similar to those for subaddresses. Mode codes 0 through 15 (0x0F) do not
have an associated data word, so data structures for these mode code values have just a Message Information Word and
Time-Tag Word. The Message Information Word is stored at the memory address specified by the descriptor table Data
Pointer. Mode codes 16 through 31 (0x10 through 0x1F) have one associated data word. The Message Information Word is
stored at the memory address specified by the descriptor table Data Pointer, and the Time-Tag Word is stored in the following
location. The data word is stored at the memory address specified by the Data Pointer plus two locations.
RECEIVE MODE COMMAND
MESSAGE INFORMATION WORD
The receive mode command data structure contains a Message Information Word, a Time-Tag Word and may contain one
Data Word. If a receive mode command has a data word, the device may apply the data as defined by MIL-STD-1553, plus
store the received single mode data word at the address specified by the Data Pointer, plus two locations. Refer to data sheet
section entitled “Mode Command Action Summary”.
Here is an example data structure for a receive mode command with data (mode code values 0x10 through 0x1F). Notice that
the Data Pointer points to the data structure starting address, not the mode data word. The data pointer is located in the receive
mode command’s Descriptor Block, fully described later:
Three receive mode commands with data are not defined under MIL-STD-1553B. These are MC16, MC18 and MC19 (mode
codes 0x10, 0x12 and 0x13 respectively). However the device responds “in form” if illegal command detection is not used
(corresponding bits in Illegalization Table are logic 0)
For mode code commands without data, the data structure contains only the Message Information Word and Time-Tag Word.
4-0
Data pointer equals 0x0500
——
MERR
WASBSY
ILCMD
——
RTRT
BUSID
WC4:0
Not used.
Message Error.
This bit is asserted when message error status change occurs during command processing. See bits
12 and 13 for details
Was Busy Status.
This bit is asserted when the terminal responds to the transmit command with BUSY status, due to
global BUSY bit set in 1553 Status Bits Register, or command-specific MKBUSY bit set in the
descriptor table Control Word. No data words were transmitted.
Illegal Command Received.
This bit is asserted when the Illegalization Table bit corresponding to the received command equals
one. The Illegalization Table should only contain nonzero values when “illegal command detection” is
being applied. See section entitled Illegalization Table for further information.
Not used.
Remote Terminal to Remote Terminal Transfer.
Assertion of this bit indicates the transmit command was an error-free RT-to-RT transfer.
Bus Identification.
If this bit equals zero, message was transacted on Bus A. If bit equals one, it was transacted on Bus B.
Word Count.
This 5-bit field contains the word count extracted from the command word. Zero indicates 32 words.
———>
———>
Hex Address
Data Buffer
0x0500
0x0501
0x0502
HOLT INTEGRATED CIRCUITS
.
HI-6120, HI-6121
and
the UMCINV bit in Configuration Register 1 is logic 0.
Word Description
Message Information Word
Time-Tag Word
Mode Data Word
49
Word Is Written By
Device, after message completion
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