Omega 1002 User Manual
4.2 The 8254 Timer
The OME-PCI-1002 series provide 3 independent 16-bit
timer/counters. Each timer has a different function. Timer 0 is used as
Pacer 0. Timer 1 is used as Pacer 1. Timer 2 is used as the machine
independent timer. The block diagram is given as follows:
Pacer 0. Timer 1 is used as Pacer 1. Timer 2 is used as the machine
independent timer. The block diagram is given as follows:
Figure 4-2. 8254 Block Diagram.
4.3 The A/D trigger
The block diagram of the A/D trigger is shown below:
Timer 0
Timer 1
Timer
Local Data Bus
D0…D7
EN
EN
EN
User
CLK
CLK
CLK
4 M Hz
OUT1
OUT2
OUT3
VCC
Pacer 0
Pacer 1
8254
Status
Mux
8254
Timer 1
EN
CLK
4M-Hz
PR
RS
Q
D
External Trigger
Software Trigger
8254
Timer 0
External
Trigger.
Trigger.
0
1
1
Figure 4-3. A/D Trigger Controller.
Select
To A/D
Trigger Select
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