ADLINK ACL-8454/12 User Manual
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• Introduction
The card also provides digital output and input port. There are 8 digital
output channels and these channels can be used to control the external
devices. There are digital input channels and these channels are shared the
same signal lines with the external clock and the external gate signals.
Whenever the external clock or gate signals are not used, they can be
dedicatedly used as D/I. There are at least 8 D/I bits under default setting of
the ACL-8454 because only two 8254 chips are used.
ACL-8454 provides one interrupt signal which comes from one of four
internal or external interrupt sources. Three internal interrupt sources come
from the counter output. One external interrupt source shares with one D/I
pin. The interrupt can be used for watchdog timer or other applications. One
of the 11 interrupt levels on the AT-bus can be selected by setting jumper.
Figure 1.1 shows the block diagram of the ACL-8454.
Optional
8254
chip #1
8254
chip #2
8254
chip #3
8254
chip #4
8 bits
Digital Input
8 bits
Digital Output
8
data bus
buffer
address
decoder
Double
interrupt
level selector
(OUT)
3
address
switch
Clock
System
(CLK,GATE)
6
jumpers
(OUT)
2
(CLK,GATE)
2
(OUT)
3
(CLK,GATE)
6
(OUT)
2
(CLK,GATE)
2
8
PC
bus
37 pin D
-t
yp
e c
onnector
8 bits
Digital Input
8
Figure 1.1. Block diagram of the ACL-8454