HI-6120 HOLTIC [Holt Integrated Circuits], HI-6120 Datasheet - Page 39

• Manufacturer Part Number: HI-6120
• Description: MIL-STD-1553 Remote Terminal ICs
• Manufacturer: HOLTIC [Holt Integrated Circuits]

Function 1: When Configuration Register 2 is written causing a 0 to 1 transition of the TTLOAD bit, the value contained
in the Time-Tag Utility register is loaded into the Time-Tag counter.
Function 2: If the TTINT1 bit in the Interrupt Enable register is set, the Interrupt Pending register TTINT1 bit is set and
the INTHW interrupt output is asserted each time the free-running Time-Tag counter value matches the value stored
in the Time-Tag Utility register.
5.15. Bus A Select Register (0x0012)
This 16-bit register is Read-Write and is fully maintained by the host. This register is cleared after MR pin master
reset, but is not affected by SRST software reset. The Bus A Select register is only used when the MCOPT4 bit
in Configuration Register 2 equals 0. This MCOPT4 setting means the device automatically fulfills mode commands
MC20 (decimal) “selected transmitter shutdown” or MC21 “override selected transmitter shutdown”.
on Bus B, the inactive bus is Bus A. The device compares the received mode data word to the contents of the Bus
A Select register to determine whether inactive Bus A is selected for “transmitter shutdown” or “transmitter shutdown
override”. (Bus shutdown or shutdown override can only occur for the inactive bus.) If the data word matches the
value stored in the Bus A Select register and MCOPT4 equals 0, the device automatically fulfills MC20 “transmitter
shutdown” or MC21 “shutdown override” without host assistance: If the mode command received was MC20, the
Transmit Shutdown A bit in the built-in test (BIT) word is asserted. If mode command MC21 was received, the Transmit
Shutdown A bit in the BIT Word is negated. Refer to Configuration Register 2 description of MCOPT4 bit for additional
details.
5.16. Bus B Select Register (0x0013)
This 16-bit register is Read-Write and is fully maintained by the host. This register is cleared after MR pin master
reset, but is not affected by SRST software reset. The Bus B Select register is only used when the MCOPT4 bit
in Configuration Register 2 equals 0. This MCOPT4 setting means the device automatically fulfills mode commands
MC20 (decimal) “selected transmitter shutdown” or MC21 “override selected transmitter shutdown”.
on Bus A, the inactive bus is Bus B. The device compares the received mode data word to the contents of the Bus B
Select register to determine whether inactive Bus B is selected for “transmitter shutdown” or “transmitter shutdown
override”. If the data word matches the value stored in the Bus B Select register and MCOPT4 equals 0, the device
automatically fulfills MC20 “transmit shutdown” or MC21 “shutdown override” without host assistance: If the mode
“Transmitter shutdown” or “shutdown override” can only occur for the inactive bus. If either mode command is received
“Transmit shutdown” or “shutdown override” can only occur for the inactive bus. If either mode command is received
MSB
MSB
MSB
15 14 13 12 11 10 9
15 14 13 12 11 10 9
15 14 13 12 11 10 9
15 14 13 12 11 10 9
15 14 13 12 11 10 9
15 14 13 12 11 10 9
BUS A SELECT REGISTER15:0
BUS B SELECT REGISTER15:0
TIME-TAG UTILITY15:0
8
8
8
8
8
8
7
7
7
7
7
7
6
6
6
6
6
6
5
5
5
5
5
5
HOLT INTEGRATED CIRCUITS
4
4
4
4
4
4
HI-6120, HI-6121
3
3
3
3
3
3
2
2
2
2
2
2
1
1
1
1
1
1
0
0
0
0
0
0
39
LSB
LSB
LSB