Configuration and Installation Chapter 2

Lab-NB User Manual 2-24 © National Instruments Corporation

Figure 2-18 shows the timing requirements for the GATE and CLK input signals and the timingspecifications for the OUT output signals of the 8253.
tsc tpwh tpwl
tgsu tgh
tgwh tgwl
toutc
toutg
CLK
GATE
OUT
VOH
VIH
VIL
VIH
VOL
VIL
tsc
tpwh
tpwl
tgsu
tgh
tgwh
tgwl
toutg
toutc
clock period
clock high level
clock low level
gate setup time
gate hold time
gate high level
gate low level
output delay from clock
output delay from gate
380 nsec min
230 nsec min
150 nsec min
100 nsec min
50 nsec min
150 nsec min
100 nsec min
300 nsec min
400 nsec min
Figure 2-18. General-Purpose Timing SignalsThe GATE and OUT signals in Figure 2-18 are referenced to the rising edge of the CLK signal.