Contec CNT24-4D(PCI), User Manual

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I/O Port Bit Assignment
CNT24-4D(PCI)
45
Programmable Timer
(Command timer data:17H, Timer start:18H)
17H
18H
Programmable timer setting data
D7 D6 D5
D4
D3 D2 D1
D0
Not in use START
D7
D6 D5 D4 D3 D2 D1
D0
The programmable timer can generate interrupts at cycles according
to 32-bit setting data. To operate with the timer, you need to set 32
data and set the START bit to "1."
To set the programmable timer, output 17H with output port +0 and
set timer data with output port +1. Since the timer data consists of
32 bits, output the data by 8 bits four times, starting from the lower
bits. The timer can be set in a range of 1msec through 200sec.
To start the timer output timer start command 18H with output port
+0 and set an appropriate bit to "1" with output port +1. To stop
the timer, set this bit to "0."
The relationship between programmable timer setting data and
timer interrupt cycles is as shown in Table 5.7. The following is
an example program to set the programmable timer to one second.
OUT Lead a0H, 17H (select timer setting)
OUT Lead a1H, FFH (least significant)
OUT Lead a1H, 2CH (lower)
OUT Lead a1H, 31H (higher)
OUT Lead a1H, 01H (most significant)
OUT Lead a0H, 18H (select timer start)
OUT Lead a1H, 1H (timer start)
Note!
When initialized, the timer is stopped.