ADLINK ACL-8454/12 - Manual (Page 31)

Installation & Configurations • 23
2.15 Notes for Installing More 8254 Chips
The user can install 8254 chips to ACL-8454 card by yourself. Before install
the additional 8254 chip, please make sure the ACL-8454 card is removed
from the PC slot, no power is applied and no external daughter board is
attached.
When plugging 8254 chips, please check the pin of chips must not be fold
and install the chip into the socket carefully. After installing the chip, please
configure the jumper setting of the ACL-8454 card according to your
application. At first the clock source of counter #7 ~ #10 should be set. The
gate source of counter #7~#10 cannot be configured, however, user should
notice whether if any external gate source or digital signal is connected to
the signals. The un-wanted signal may control the gate source of the
counters can cause your application fail.
The low IRQ source should also be checked because the counter #12 is
installed and COUT12 can only be used as internal interrupt source if 8254
chip #4 is installed. Please take care the issues mentioned above.