在Q II环境下出现了如下警告,请教解决办法
在Q II环境下出现了如下警告,请教高人给予指点解决办法:----------------------------------------------------------------------
1. Warning:Found 6 output pins without output pin load capacitance assignment
说是缺少容性负载,怎么样设置容性负载值才是合理的?
2. Critical Warning: Timing requirements were not met.
不满足时序要求,这个问题好像比较严重。在TimeQuest下,将Tsu、Th等设置为多少事合理的?
3. Warning: Skipped module PowerPlay Power Analyzer due to the assignment FLOW_ENABLE_POWER_ANALYZER
由于分配FLOW_ENABLE_POWER_ANALYZER,跳过模块“PowerPlay功耗分析仪”。
如何解决?
4. Warning: Parallel compilation is not licensed and has been disabled
5. Warning: Feature LogicLock is only available with a valid subscription license. You can purchase a software subscription to gain full access to this feature.
是由于软件是免费版本的原因么?如果是,影响逻辑综合结果么?如果影响,如何改进之?
6. Critical Warning: Synopsys Design Constraints File file not found: 'mapan_model.sdc'. A Synopsys Design Constraints File is required by the TimeQuest Timing Analyzer to get proper timing constraints. Without it, the Compiler will not properly optimize the design.
这也是一个严重警告。如何生成.sdc文件?.sdc文件中的Tsu、Th等设置为多少事合理的? 我用的最新版,还没有碰到过这些问题,不过我也想知道怎么解决哈 我用的最新版,还没有碰到过这些问题,不过我也想知道怎么解决哈 我查了下,网上说:
Warning:Found 4 output pins without output pin load capacitance assignment
原因:没有给输出管教指定负载电容
解决方法:该功能用于估算TCO和功耗,可以不理会,也可以在Assignment Editor中为相应的输出管脚指定负载电容,以消除警告 。 "Critical Warning: Timing requirements are not met."
"Critical Warning: Found minimum pulse width or period violations. See Report Minimum pulse width for more information."
"Critical Warning: The following clock transfers have no clock uncertainty assignment. For more accurate results, apply clock uncertainty assignments or use the derive_clock_uncertainty command.
Critical Warning: From clk (Rise) to clk (Rise) (setup and hold)"
Re: Critical Warning: Timing requirements not met
Add "derive_clock_uncertainty" to your .sdc. (In newer versions of Quartus this command runs automatically, but you still get a warning.)
You have failing paths in your design. Launch TimeQuest, run the macro on the left side called Report All Summaries. Find the red, right-click and do a Report Timing on the failing paths.
(Note that Report Minimum Pulse Width failures stem from "datasheet" numbers. For example, a memory might be spec'd to run at 400MHz, and if you drive it with a clock at 425MHz, you get this failure. It's not so much static timing analysis of individual components, but specs on how fast something can run. Common ones are memory blocks, I/Os, clock trees and dynamic reconfiguration ports(such as PLL/Transceiver reconfiguration). 回复 4# 白开水的噩梦
多谢^_^ 多谢各位的参与。在另一个论坛,一位高手(Mason同志)的解答,拿来与大家共享:
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我只能回答部分,可做参考:
1. 这个问题大可不必在意。但具体Pin Load要设多少,没有太多的规定。不设也是可以的。
2. Critical Warning一般都比较重要。Tsh, Th不是说设成多少是合理的。而是分析出来的slack是否大于零,这才是关键。只要slack大于零就可以。但前提是时序约束要做好,比如内部的时序就是时钟约束,IO的时序约束就是Input/Output Delay约束。芯片内部寄存器的Tsh, Th是由芯片的工艺决定的,不能设。能设的Tsh和Th是在用Classic时序分析工具的时候,对IO做的约束。用TimeQuest作为时序分析工具的话,IO约束是Input Delay Max/Min。
3.跳过Power Play分析不是很关键的问题。如果你想分析功耗,在编译完成过后大可在Processing菜单下打开Power Play工具,再重新分析一下。
4.这个告警可能是由于你的软件是Web版的,或者是破解不全。但是问题不大,编译时间稍微长一点而已。
5. 这个报警跟上面的报警原因可能是一样的。
6.这个Critical Warning是由于你在选择时序分析工具的时候选了TimeQuest。但是又没定义建立时序约束的SDC文件。如果没有这个文件的话,那么编译器会自动在每个时钟上加1GHZ的约束。导致最后编译的结果时序紊乱。建议重新加一下时序约束为好,不然很容易出问题。
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