The maximum clock speed I understand that a PIC can count at is 50 MHz - correct? I want to count at higher frequencies - up to 500 MHz and I'm looking to use a logic counter to divide 500 by 16 and give an input frequency into the PIC of 500/16 = 31.25 MHz. There's a 7400 series chip, the 74F161 that divides by 16 but the max i/p frequency is 100 MHz. Are there any 7400 series other than F that can go faster or any equivalents that y'all know of? Can anyone point me to a counter, ideally pre-settable and with accessible (to read) outputs, that could take a clock input for counting faster than 100 MHz and divide by 16? Ted Mawson PICman@portfoliopm.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.