外部用的是有源晶振，20M，产生错误：Error: Input pin "CLK" feeds inclk ports of PLL "altpll0:inst2|altpll:altpll_component|pll" and other PLLs -- the input pin cannot feed inclk ports of more than 1 PLL


Error: Input pin "CLK" feeds inclk ports of PLL "altpll1:inst1|altpll:altpll_component|pll" and other PLLs -- the input pin cannot feed inclk ports of more than 1 PLL


官网解释：http://www.altera.com/support/kdb/solutions/rd02012010_744.html
不知道怎么解决，望前辈指点。 此帖出自小平头技术问答