National Instruments NI 6014 - Manual (Page 61)

Chapter 4 Connecting Signals
© National Instruments Corporation 4-35 NI 6013/6014 User Manual
GPCTR0_GATE Signal
Any PFI pin can externally input the GPCTR0_GATE signal, which is
available as an output on the PFI9/GPCTR0_GATE pin.
As an input, GPCTR0_GATE is configured in the edge-detection mode.
You can select any PFI pin as the source for GPCTR0_GATE and configure
the polarity selection for either rising or falling edge. You can use the gate
signal in a variety of different applications to perform actions such as
starting and stopping the counter, generating interrupts, saving the counter
contents, and so on.
As an output, GPCTR0_GATE reflects the actual gate signal connected to
general-purpose counter 0, even if the gate is being externally generated by
another PFI. This output is set to high-impedance at startup.
Figure 4-30 shows the timing requirements for GPCTR0_GATE.
Figure 4-30. GPCTR0_GATE Signal Timing in Edge-Detection Mode
GPCTR0_OUT Signal
This signal is available only as an output on the GPCTR0_OUT pin.
GPCTR0_OUT reflects the terminal count (TC) of general-purpose
counter 0. You have two software-selectable output options—pulse on TC
and toggle output polarity on TC. The output polarity is software-selectable
for both options. This output is set to high-impedance at startup.
Figure 4-31 shows the timing of GPCTR0_OUT.
Note When using external clocking mode with correlated DIO, this pin is used as an input
for the external clock.
Rising-Edge
Polarity
Falling-Edge
Polarity
t
w
= 10 ns minimum
t
w