clock gating的部分我是忽略不去看的，通常这个hold time violation会发生在gating cell的地方 clock gating一般为了预防glitch的发生会用一级DFF用负缘去latch住enable讯号，在用这个DFF的输出 去和Clock作AND。而这个AND就会是gating cell。因此你可以看到，在你的timing report中上面的clock是用rising edg...
Logical Clock Gating:通过逻辑综合自动实现,一般是在register clock pin上。 Global Clock Gating:通过控制某一或者某几个模块的clock enable信号实现。 04 — XOR Self Gating XOR Self Gating是一种新的clock gating方法,当寄存器的输入信号D与前一时刻的输出信号Q相同时,可以将clock信号gating住,减少无效翻转。 X...
秒杀数字后端实现中clock gating使能端setup violation问题 数字芯片设计实现中修复setup违例的方法汇总 深入浅出讲透set_multicycle_path,从此彻底掌握它 Hold影响 由于hold check是同沿检查。因此clock jitter对hold没有影响。因此在芯片timing signoff时,往往hold 的uncertainty会比较小。 考虑clock jitter的实现策略 通...
设置set_clock_gating_check之后,工具在优化时会尽量满足门控时钟的时序需求,避免setup和hold的violation。 AND-based clock gating OR-based clock gating 针对AND-based clock gating,当出现时序违例时,会出想下面这种情况
秒杀数字后端实现中clock gating使能端setup violation问题 数字芯片设计实现中修复setup违例的方法汇总 深入浅出讲透set_multicycle_path,从此彻底掌握它 Hold影响 由于hold check是同沿检查。因此clock jitter对hold没有影响。因此在芯片timing signoff时,往往hold 的uncertainty会比较小。
我们也可以使用set_clock_gating_check指令设置setup与hold值。图5与图6分别是clock gating check setup与hold的timing报告。由于UAND0/A变得太快,在CLKB为高时变化,hold gating check有violation。 图4 上升沿产生gating信号时序图 图5 上升沿产生gating信号setup check report...
signal based on at least one Boolean signal and the system clock signal or a preprocessed system clock signal, wherein the clock gating circuitry comprises physical connections of small capacitance such that tapping of at least one of the physical connections results in a hold-time violation. Also...
The problem is these 15 sub-clocks must be synchronized and now there is some timing violation which seems that they are not. I wonder if there is some constraints to do before synthesis or some smarter way in implenment the clock gating for this design Thank you very much:) :) :...
signal based on at least one Boolean signal and the system clock signal or a preprocessed system clock signal, wherein the clock gating circuitry comprises physical connections of small capacitance such that tapping of at least one of the physical connections results in a hold-time violation. Also...
I hope Quartus will automatically take care of the hold time violation due to clock skew. I will analyze it a bit further. Translate 0 Kudos Copy link Reply Altera_Forum Honored Contributor II 10-01-2010 06:05 AM 2,215 Views Do you actually need to use clk/2 as a clo...