Cyclone IV不是说可以倍频到1GHz以上吗?可是我使用PLL配置输出1Ghz就不可以了,为什么呢?
警告:Critical Warning (15534): PLL clock output sys_pll:sys_pll_inst|altpll:altpll_component|sys_pll_altpll:auto_generated|wire_pll1_clk[0] feeding the core has illegal output frequency of 1000.0 MHz that must be less than 472.6 MHz |