Chapter 4 Signal Connections
National Instruments Corporation 4-51 AT-MIO/AI E Series User Manual
GPCTR1_UP_DOWN Signal

This signal can be externally input on the DIO7 pin and is not available

as an output on the I/O connector. General-purpose counter 1 counts

down when this pin is at a logic low and counts up at a logic high. This

input can be disabled so that software can control the up-down

functionality and leave the DIO7 pin free for general use. Figure 4-37

shows the timing requirements for the GATE and SOURCE input

signals and the timing specifications for the OUT output signals of your

AT E Series board.

Figure 4-37. GPCTR Timing Summary

SOURCE VIH
VIL
VIH
VIL
tsc tsp tsp
tgsu tgh
tgw
GATE
tout
OUT VOH
VOL
sc
t
t
t
t
t
t 50 ns minimum
sp 23 ns minimum
gsu 10 ns minimum
gh 0 ns minimum
gw 10 ns minimum
out 80 ns maximum
Source Clock Period
Source Pulse Width
Gate Setup Time
Gate Hold Time
Gate Pulse Width
Output Delay Time