Real-Time Clock Interrupt - Digital Equipment KXJ11-CA Installation Manual

2.16 Real-Time Clock Interrupt
SLU1 (the on-board DLART) can generate real-time clock interrupts at frequencies of
50 and 60 Hz. Jumpers M52, M53, and M54 select either the 50 Hz or the 60 Hz
real-time clock as input to the interrupt control logic. If interrupts are enabled, each
clock "tick" results in a maskable priority level 6 interrupt request to the on-board
J-11. The location of the real-time clock interrupt jumpers is shown in Figure 2-19. A
real-time clock rate of 60 Hz is specified as part of the factory-shipped configuration.
Jumper Connection
o
o
M54
M53
M52
M54
M53
M52
Description
60 Hz real-time clock selected
*
50 Hz real-time clock selected
o M54
o M53
o M52
. . . . . 0
1
~
. . ..
.
.. . ...
..
D , . . , ; :
D
MR-16229
Figure 2-19 Real-Time Clock Interrupt
*
Factory-shipped configuration
2-25