ICS PCI-WDT 500, Руководство по эксплуатации продукта

Страница: 41 / 44

Manual Number: 00650-144-1 Page 28
PCI-WDT 500/501 Manual
Mode 3: Square Wave Generator
Like mode 2, this mode operates periodically. The output is high for half of the count and low for the
other half. If the count is even, then the output is a symmetrical square wave. If the count is odd,
then the output is high for (N+1)/2 counts and low for (N-1)/2 counts. Periodic triggering or fre-
quency synthesis are two possible applications for this mode. Note that, in this mode, to achieve the
square wave, the counter decrements by two for the total loaded count, then reloads and decre-
ments by two for the second part of the waveform.
Mode 4: Software Triggered Strobe
This mode sets the output high and, when the count is loaded, the counter begins to count down.
When the counter reaches zero, the output will go low for one input period. The counter must be
reloaded to repeat the cycle. A low gate input will inhibit the counter.
Mode 5: Hardware Triggered Strobe
In this mode, the counter will start counting after the rising edge of the trigger input and will go low
for one clock period when the terminal count is reached. The counter is retriggerable. The output
will go low until the full count after the rising edge of the trigger.