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Altera_Forum
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16 years ago

HELP ME about EP2C20Q240C8,PLEASE!

HI ALL I'm using the cycloneII(EP2C20Q240C8).I want to know what the difference the pin 178 and the others.when i use the pin 178 as LVTTL output,it cannot output a wave (frequency about 25MHz whe...
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Altera_Forum
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16 years ago

Pin 178 can be either normal IO or the output of a pll: PLL2_OUTn. Are you driving this pin from logic (e.g as the output of a divider) or directly from the pll? In the latter case it doesn't work: see page 20 of "Pin Information for the Cyclone® II EP2C15A, EP2C20 and EP2C20A Devices.pdf" (http://www.altera.com/literature/dp/cyclone2/ep2c20_ep2c15a_ep2c20a.pdf).