HI-6121PQMF HOLTIC [Holt Integrated Circuits], HI-6121PQMF Datasheet - Page 47

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

MESSAGE DATA BUFFERS, Cont.
RECEIVE SUBADDRESS COMMAND
MESSAGE INFORMATION WORD
For receive subaddress commands, the device stores the received data words plus two additional words. The device adds a
receive subaddress Message Information Word and a Time-Tag Word to the received data words. The device stores the
Message Information and Time-Tag words ahead of the data words associated with the receive command, as shown below. If
message error occurs, the RT stores only the receive subaddress Message Information Word and Time-Tag Word. Once a
message error is detected, the device sets the MERR bit in the receive subaddress Message Information word. When this
occurs, all data words are considered invalid. Whenever the receive subaddress Message Information Word MERR bit is set,
the host should disregard the record’s data word(s).
Here is an example data structure for a 3-word receive command. Notice that the receive subaddress Data Pointer points to
the data structure starting address, not the first data word. The data pointer is located in the receive subaddress command’s
Descriptor Block, fully described later:
The following bits comprise the receive subaddress Message Information Word:
Bit No.
15
14
13
12
11
10
9
MSB
Data pointer equals 0x0500
15 14 13 12 11 10 9
Mnemonic Function
TMOERR
IWDERR
GAPERR
WCTERR Word Count Error
SYNERR
MERR
WASBSY
Time-Out Error.
This bit is asserted for RT-RT receive messages when the transmitting
word and data transmission before time-out occurs, per TOSEL0-1 bits in Configuration Register 2.
Invalid Word Error.
Assertion of this bit indicates Manchester error or parity error was observed in a received data word.
Gap Error.
Assertion of this bit indicates bus activity was detected immediately after the last expected receive
data word or that a gap occurred before all expected data words were received.
This bit is asserted if command is received with less data words than the command word specifies.
For example, a receive command for three data words is received with two contiguous data words.
Sync Error.
This bit is asserted when an incorrect (command/status) sync type occurs in received data words.
Message Error.
7 and 11-15 for details.
Was Busy.
This bit is asserted when the terminal responds to the receive 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. Received data words were buffered normally.
This bit is asserted when message error status change occurs during command processing. See bits
8
———>
———>
7
6
Hex Address
Data Buffer
5
0x0500
0x0501
0x0502
0x0503
0x0504
4
HOLT INTEGRATED CIRCUITS
3
2
HI-6120, HI-6121
1
0
Word Description
Message Information Word
Time-Tag Word
Data Word 1
Data Word 2
Data Word 3
LSB
47
The data words are written after message
completion when Configuration Register 2
TRXDB is 1, otherwise written when received.
Device Writes Word...
After message completion
After message completion (note)
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terminal fails to start its status
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