NuDAQ PCI-8554, Руководство пользователя

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Installation
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21
2.13 Debounce System
Debounce system is used to eliminate bounce phenomenon. If
external clock is used, user can set jumper
JP1 ~ JP11 to select if
debounce system is used or not used. If debounce system is used,
the debounce outp ut signal will be the same state as the input only if
the input signal keep the same state for four
DB_CLK , otherwise the
input signal will be treated as glitch and the debounce output signal
will keep previous state, figure 2.11 show you the how to set th ese
jumpers, figure 2.12 show you how to select
DB_CLK , figure 2.13
show you the basic theorem of debounce system.( Note: DB_CLK
can’t be higher than 2MHz. )
ECK n
ECLK n
debounce
system
DB_CLK
JP n
n=1~10
EXTINT
E_INT
debounce
system
DB_CLK
JP11
Figure 2.11 Structure of JP1 ~ JP11
2MHz
DB_CLK
COUT11
select by function
"_8554_SET_DBCLK"
Figure 2.12 Clock Source of DB_CLK