-early表示延时的可能最小值; -late 表示延时的可能最大值。 例如, set_clock_latency –source –late 1.234 sys_clk set_clock_latency –source –early 1.10 sys_clk … the board-level clock delay to sys_clk can be as late as 1.234ns and as early as 1.10ns early. 可见,early和late分别表示...
-early表示延时的可能最小值; -late 表示延时的可能最大值。 例如, set_clock_latency –source –late 1.234 sys_clk set_clock_latency –source –early 1.10 sys_clk … the board-level clock delay to sys_clk can be as late as 1.234ns and as early as 1.10ns early. 可见,early和late分别表示...
刚开始学dc,有些用法比较模糊,记录一下set_clock_latency与set_clock_uncertainty的理解:1,set_clock_latency用于描述时钟源到寄存器时钟输入端的延迟,包括source和network延迟,在pre-layout约束时,同时使用;在post-layout时,准确的说,cts之后,只设置source latency,因为network 延迟已经包含在sdf里了。如法如下:...
该指令允许用户为时钟源到时钟定义点(例如,时钟端口)设置源延迟,从而影响到整个时钟树的行为。值得注意的是,设计者可以使用-source选项专门定义源延迟,而network延迟则由时序分析工具自动计算。这一区别在复杂设计中尤其重要,能够让设计者更精准地把控时序问题。 在某个具体的交付项目中,由于选用了新的SRAM型号,设计者...
There are two forms of clock latency: clock source latency, and clock network latency. Source latency is the propagation delay from the origin of the clock to the clock definition point (for example, a clock port). Network latency is the propagation delay from a clock definition point to a...
The constraints file has a set_clock_latency -source command. If it is removed, then 20 builds will pass. We can't do a gate level simulation as the design includes both a PCIE and a DDR2 controller. Why does the set_clock_latency constraint impacts the design implementation 20...
I understand how to use -source to model the propagation delays of the external clocks through the board and clock buffer chips. What I don't get is how to use the "network" latency setting. Based on the documentation, this is supposed to represent "Network latency is the time a clock ...
There are two forms of clock latency: clock source latency, and clock network latency. Source latency is the propagation delay from the origin of the clock to the clock definition point (for example, a clock port). Network latency is the propagation delay from a clock definition point to a...
To specify source latency to any clock ports in your design, use the set_clock_latency command. Note: The Timing Analyzer automatically computes network latencies. Therefore, you can only characterize source latency with the set_clock_latency command using the -source option. Related...
To specify source latency to any clock ports in your design, use the set_clock_latency command. Note: The Timing Analyzer automatically computes network latencies. Therefore, you can only characterize source latency with the set_clock_latency command using the -source option. Related...