ADLINK Technology NuDAQ PCI-9222, Руководство пользователя

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48 Operation Theory
General Purpose Timer/Counter
The PCI-9222/PCI-9223 comes with three general purpose timer/
counter sets featuring:
X
Count up/down controlled by hardware or software
X
Programmable counter clock source (internal clock up to
80 MHz, external clock up to 10 MHz)
X
Programmable gate selection (hardware or software control)
X
Programmable input and output signal polarities (high active
or low active)
X
Initial Count can be loaded from a software application
X
Current count value can be read-back by software without
affecting circuit operation.
Basic Timer/Counter Functions
Each timer/counter has three inputs that can be controlled via
hardware or software applications. They are clock input
(GPTC_CLK), gate input (GPTC_GATE), and up/down control
input (GPTC_UD). The GPTC_CLK input provides a clock source
input to the timer/counter. Active edges on the GPTC_CLK input
make the counter increment or decrement. The GPTC_UD input
Definition Pin # Definition
GPTC_CLK0 34 68 GPTC_CLK2
GPTC_UD0 33 67 GPTC_UD2
GPTC_GATE0 32 66 GPTC_GATE2
GPTC_AUX0 31 65 GPTC_AUX2
GPTC_CLK1 30 64 GPTC_CLK3
GPTC_UD1 29 63 GPTC_UD3
GPTC_GATE1 28 62 GPTC_GATE3
GPTC_AUX1 27 61 GPTC_AUX3
DGND 26 60 DGND
GPTC_OUT0 25 59
GPTC_OUT1 24 58
GPTC_OUT2 23 57
GPTC_OUT3 22 56
... ...
1 35
Table 4-6: Timer/Counter Mode Pins in CN1