HI-6121PQMF HOLTIC [Holt Integrated Circuits], HI-6121PQMF Datasheet - Page 48

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

MESSAGE DATA BUFFERS, Cont.
8
7
6
5
4-0
TRANSMIT SUBADDRESS COMMAND
MESSAGE INFORMATION WORD
The external host is responsible for organizing the data packet (i.e., storing N data words) in shared RAM and initializing the
applicable data pointer. The host must allocate two memory locations at the starting address of the data record for device
storage of the transmit subaddress Message Information Word and Time-Tag Word.
Here is an example data structure for a 3-word transmit command. Notice that the Data Pointer points to the data structure
starting address, not the first data word. The data pointer is located in the transmit subaddress command’s Descriptor Block.
The following bits comprise the transmit subaddress Message Information Word.
Bit No.
15-14
13
12
MSB
Data pointer equals 0x0500
15 14 13 12 11 10 9
X
X
TXRTERR
ILCMD
RTRT
BUSID
Mnemonic Function
——
GAPERR
WCTERR Word Count Error
WC4:0
X
Illegal Command Received.
This bit is asserted when the Illegalization Table bit corresponding to the received command is logic
1. The Illegalization Table should only contain nonzero values when “illegal command detection” is
being applied. See section entitled Illegalization Table for further information.
RT-RT Transmit Remote Terminal Error.
This bit is set when the terminal decodes a valid RT-RT receive command, but one of four potential
errors is detected in
RT31. (2) the CW2 T/ bit equals 0, (3) the CW2 subaddress is a mode command indicator, 00000 or
11111, or (4) CW2 has same non-broadcast terminal address as receive command word CW1.
The TXRTERR bit is also set when status word received from the transmitting terminal
parity error) or bits 15:11 in the status word reflect
Remote Terminal to Remote Terminal Transfer.
Assertion of this bit indicates the receive 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.
Not used.
Gap Error.
Assertion of this bit indicates bus activity was detected immediately after the transmit command
word, when a gap was expected.
This bit is asserted if command is received with unexpected data word(s).
8
———>
———>
X
7
6
Hex Address
Data Buffer
5
0x0500
0x0501
0x0502
0x0503
0x0504
4
HOLT INTEGRATED CIRCUITS
the second command word, CW2
R
3
2
HI-6120, HI-6121
1
0
Word Description
Message Information Word Device, after message completion
Time-Tag Word
Data Word 1
Data Word 2
Data Word 3
LSB
48
the wrong RT address (does not match CW2).
: (1) CW2 is addressed to broadcast address
Word Is Written By
Host, prior to terminal’s data transmit
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is invalid (e.g.,
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