Verilog 常见错误汇总
1.Found clock-sensitive change during active clock edge at time <time> on register "<name>"
原因:vector source file中时钟敏感信号(如:数据,允许端,清零,同步加载等)在时钟的边缘同时变化.而时钟敏感信号是不能在时钟边沿变化的.其后果为导致结果不正确.
措施:编辑vector source file
2.Verilog HDL assignment warning at <location>: truncated with size <number> to match size of target (<number>
原因:在HDL设计中对目标的位数进行了设定,如:reg[4:0] a;而默认为32位, 将位数裁定到合适的大小
措施:如果结果正确,无须加以修正,如果不想看到这个警告,可以改变设定的位数
3.All reachable assignments to data_out(10) assign ‘0‘, register removed by optimization
原因:经过综合器优化后,输出端口已经不起作用了
4.Following 9 pins have nothing, GND, or VCC driving datain port -- changes to this connectivity may change fitting results
原因:有9个脚为空或接地或接上了电源
措施:有时候定义了输出端口,但输出端直接赋‘0’,便会被接地,赋‘1’接电源. 如果你的设计中这些端口就是这样用的,那便可以不理会这些warning
5.Found pins functioning as undefined clocks and/or memory enables
原因:是你作为时钟的PIN没有约束信息.可以对相应的PIN做一下设定就行了. 主要是指你的某些管脚在电路当中起到了时钟管脚的作用,比如flip-flop的clk 管脚,而此管脚没有时钟约束,因此QuartusII把“clk”作为未定义的时钟.
措施:如果clk不是时钟,可以加“not clock”的约束;如果是,可以在clock setting当中加入;在某些对时钟要求不很高的情况下,可以忽略此警告或在这里修改:Assignments>Timing analysis settings...>Individual
clocks...>...
6.Timing characteristics of device EPM570T144C5 are preliminary
原因:因为MAXII 是比較新的元件在 QuartusII 中的時序并不是正式版的,要等 Service Pack
措施:只影响 Quartus 的 Waveform
7.Warning: Clock latency analysis for PLL offsets is supported for the current device family, but is not enabled
措施:将setting中的timing Requirements&Option-->More Timing Setting-->setting-->Enable Clock Latency中的on改成OFF
8.Found clock high time violation at 14.8 ns on register "|counter|lpm_counter:count1_rtl_0|dffs[11]"
原因:违反了steup/hold时间,应该是后仿真,看看波形设置是否和时钟沿符合steup/hold时间
措施:在中间加个寄存器可能可以解决问题
9.warning: circuit may not operate.detected 46 non-operational paths clocked by clock clk44 with clock skew larger than data delay
原因:时钟抖动大于数据延时,当时钟很快,而if等类的层次过多就会出现这种问 题,但这个问题多是在器件的最高频率中才会出现
措施:setting-->timing Requirements&Options-->Default required fmax 改小一些,如改到50MHZ
10.Design contains <number> input pin(s) that do not drive logic
原因:输入引脚没有驱动逻辑(驱动其他引脚),所有的输入引脚需要有输入逻辑
措施:如果这种情况是故意的,无须理会,如果非故意,输入逻辑驱动.
11.Warning:Found clock high time violation at 8.9ns on node ‘TEST3.CLK‘
原因:FF中输入的PLS的保持时间过短
措施:在FF中设置较高的时钟频率
12.Warning: Found 10 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew
原因:如果你用的 CPLD 只有一组全局时钟时,用全局时钟分频产生的另一个时 钟在布线中当作信号处理,不能保证低的时钟歪斜(SKEW).会造成在这个时钟 上工作的时序电路不可靠,甚至每次布线产生的问题都不一样.
措施:如果用有两组以上全局时钟的 FPGA 芯片,可以把第二个全局时钟作为另 一个时钟用,可以解决这个问题.
13.Critical Warning: Timing requirements were not met. See Report window for details.
原因:时序要求未满足,
措施:双击Compilation Report-->Time Analyzer-->红色部分(如clock setup:‘clk‘等)-->左键单击list path,查看fmax的SLACK REPORT再根据 提示解决,有可能是程序的算法问题
14.Can‘t achieve minimum setup and hold requirement <text> along <number> path(s). See Report window for details.
原因:时序分析发现一定数量的路径违背了最小的建立和保持时间,与时钟歪斜 有关,一般是由于多时钟引起的
措施:利用Compilation Report-->Time Analyzer-->红色部分(如clock hold:‘clk‘等),在slack中观察是hold time为负值还是setup time 为负值, 然后在:Assignment-->Assignment Editor-->To中增加时钟名(from
node finder),Assignment Name中增加 和多时钟有关的Multicycle 和Multicycle Hold选项,如hold time为负,可 使Multicycle hold的值>multicycle,如设为2和1.
15: Can‘t analyze file -- file E://quartusii/*/*.v is missing
原因:试图编译一个不存在的文件,该文件可能被改名或者删除了
措施:不管他,没什么影响
16.Warning: Can‘t find signal in vector source file for input pin |whole|clk10m
原因:因为你的波形仿真文件( vector source file )中并没有把所有的输入 信号(input pin)加进去,对于每一个输入都需要有激励源的
17.Error: Can‘t name logic scfifo0 of instance "inst" -- has same name as current design file
原因:模块的名字和project的名字重名了
措施:把两个名字之一改一下,一般改模块的名字
18.Warning: Using design file lpm_fifo0.v, which is not specified as a design file for the current project, but contains definitions for 1 design units and 1 entities in project Info: Found entity 1: lpm_fifo0
原因:模块不是在本项目生成的,而是直接copy了别的项目的原理图和源程序 而生成的,而不是用QUARTUS将文件添加进本项目
措施:无须理会,不影响使用
19.Timing characteristics of device <name> are preliminary
原因:目前版本的QuartusII只对该器件提供初步的时序特征分析
措施:如果坚持用目前的器件,无须理会该警告.关于进一步的时序特征分析会在后续版本的Quartus得到完善.
20.Timing Analysis does not support the analysis of latches as synchronous elements for the currently selected device family
原因:用analyze_latches_as_synchronous_elements setting可以让 Quaruts II来分析同步锁存,但目前的器件不支持这个特性
措施:无须理会.时序分析可能将锁存器分析成回路.但并不一定分析正确.其 后果可能会导致显示提醒用户:改变设计来消除锁 存器
21.Warning:Found xx output pins without output pin load capacitance assignment
原因:没有给输出管教指定负载电容
措施: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
22.Warning: Found 6 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew
原因:使用了行波时钟或门控时钟,把触发器的输出当时钟用就会报行波时钟, 将组合逻辑的输出当时钟用就会报门控时钟
措施:不要把触发器的输出当时钟,不要将组合逻辑的输出当时钟,如果本身如 此设计,则无须理会该警告
23.Warning (10268): Verilog HDL information at lcd7106.v(63): Always Construct contains both blocking and non-blocking assignments
原因: 一个always模块中同时有阻塞和非阻塞的赋值
24.Warning: Can‘t find signal in vector source file for input pin |whole|clk10m
原因：这个时因为你的波形仿真文件（ vector source file ）中并没有把所有的输入信号(input pin)加进去， 对于每一个输入都需要有激励源的
25 Warning:Output pins are stuck at VCC or GND
如果正是希望某些输出被固定置高电平或低电平或者无所谓，就不用管它，否则请检查代码。这样的输出其实没有什么意义.
26.Warning (10208): honored full_case synthesis attribute - differences between design synthesis and simulation may occur。
/* synopsys full_case */;
意思就是：,告诉合成软件你的case几乎是full case，你（designer）可以保证没有列出的case分支是永远也不会发生的。 {
目的：告诉合成软体不用去考虑没有列出的case分支，便于化简。
限制：当然只有synopsys 的合成软体可以看懂了！所以不建议用，最好还是用default。
缺点：前后仿真不一致，综合的结果和期望的不一致。
27：Warning: No exact pin location assignment(s) for 16 pins of 16 total pins
定义的管脚没有和外部的管脚连接.
28：Warning: Ignored locations or region assignments to the following nodes
Warning: Node "78ledcom[4]" is assigned to location or region, but does not exist in design
设计中没提到"78ledcom[4]" ，而分配了管脚给它。
说明：有时候运行了TCL脚本文件后需要修改，修改后有一些先前分配的管脚不需要了，如果没有delete，则会出现此提示。
解决办法：assignments->pins，把不用的管脚删除即可（TCL脚本文件里的多余管脚分配语句最好也一起delete）。
1 Warning: VHDL Process Statement warning at random.vhd(18): signal reset is in statement, but is not in sensitivity list
----没把singal放到process（）中
2 Warning: Found pins ing as undefined clocks and/or memory enables
Info: Assuming node CLK is an undefined clock
-=-----可能是说设计中产生的触发器没有使能端
3 Error: VHDL Interface Declaration error in clk_gen.vhd(29): interface object "clk_scan" of mode out cannot be read. Change object mode to buffer or inout.
------信号类型设置不对，out当作buffer来定义
4 Error: Node instance "clk_gen1" instantiates undefined entity "clk_gen"
-------引用的例化元件未定义实体－－entity "clk_gen"
5 Warning: Found 2 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew
Info: Detected ripple clock "clk_gen:clk_gen1|clk_incr" as buffer
Info: Detected ripple clock "clk_gen:clk_gen1|clk_scan" as buffer
6 Warning: VHDL Process Statement warning at ledmux.vhd(15): signal or variable "dataout" may not be assigned a new in every possible path through the Process Statement. Signal or variable "dataout" holds its previous in every path with no new assignment, which may create a combinational loop in the current design.
7 Warning: VHDL Process Statement warning at divider_10.vhd(17): signal "cnt" is read inside the Process Statement but isn‘t in the Process Statement‘s sensivitity list
-----缺少敏感信号
8 Warning: No clock transition on "counter_bcd7:counter_counter_clk|q_sig[3]" register
9 Warning: Reduced register "counter_bcd7:counter_counter_clk|q_sig[3]" with stuck clock port to stuck GND
10 Warning: Circuit may not operate. Detected 1 non-operational path(s) clocked by clock "class[1]" with clock skew larger than data delay. See Compilation Report for details.
11 Warning: Circuit may not operate. Detected 1 non-operational path(s) clocked by clock "sign" with clock skew larger than data delay. See Compilation Report for details.
12 Error: VHDL error at counter_clk.vhd(90): actual port "class" of mode "in" cannot be associated with formal port "class" of mode "out"
------两者不能连接起来
13 Warning: Ignored node in vector source file. Can‘t find corresponding node name "class_sig[2]" in design.
------没有编写testbench文件，或者没有编辑输入变量的值 testbench里是元件申明和映射
14 Error: VHDL Binding Indication error at freqdetect_top.vhd(19): port "class" in design entity does not have std_logic_vector type that is specified for the same generic in the associated component
---在相关的元件里没有当前文件所定义的类型
15 Error: VHDL error at tongbu.vhd(16): can‘t infer register for signal "gate" because signal does not hold its outside clock edge
16 Warning: Found clock high time violation at 1000.0 ns on register "|fcounter|lpm_counter:temp_rtl_0|dffs[4]"
17 Warning: Compiler packed, optimized or synthesized away node "temp[19]". Ignored vector source file node.
---"temp[19]"被优化掉了
18 Warning: Reduced register "gate~reg0" with stuck data_in port to stuck GND
19 Warning: Design contains 2 input pin(s) that do not drive logic
Warning: No output dependent on input pin "clk"
Warning: No output dependent on input pin "sign"
------输出信号与输入信号无关，
20 Warning: Found clock high time violation at 16625.0 ns on register "|impulcomp|gate1"
21 Error: VHDL error at impulcomp.vhd(19): can‘t implement clock enable condition specified using binary operator "or"
22 Error: VHDL Association List error at period_counter.vhd(38): actual parameter assigned to formal parameter "alarm", but formal parameter is not declared
-------连接表错误，形参"alarm"赋值给实参，形参没定义，可能是形参与实参的位置颠倒了，规定形参在实参之前。
23 Error: Ignored construct behavier at period_counter.vhd(15) because of previous errors
－－－－－－－－因为前一个错误而导致的错误
24 Error: VHDL error at period_counter.vhd(38): type of identifier "alarm" does not agree with its usage as std_logic type
－－－－－－－－"alarm"的定义类型与使用的类型不一致
25 Error: VHDL error at shift_reg.vhd(24): can‘t synthesize logic for statement with conditions that test for the edges of multiple clocks
-------同一进程中含有两个或多个if(edge)条件，（一个进程中之能有一个时钟沿）
26 Error: Can‘t resolve multiple constant drivers for net "datain_reg[22]" at shift_reg.vhd(19)
27 can‘t infer register for signal "num[0]" because signal does not hold its outside clock edge
28 Error: Can‘t elaborate top-level user hierarchy
29 Error: Can‘t resolve multiple constant drivers for net "cs_in" at led_key.vhd(32) ----------有两个以上赋值语句，不能确定“cs_in”的值
30 Warning: Ignored node in vector source file. Can‘t find corresponding node name "over" in design.
---------------在源文件中找不到对应的节点“over”。
31 Error: Can‘t access JTAG chain
无法找到下载链
1.Found clock-sensitive change during active clock edge at time <time> on register "<name>"
原因：vector source file中时钟敏感信号（如：数据，允许端，清零，同步加载等）在时钟的边缘同时变化。而时钟敏感信号是 不能在时钟边沿变化的。其后果为导致结果不正确。
措施：编辑vector source file
2.Verilog HDL assignment warning at <location>: truncated value with size <number> to match size of target (<number>
原因:在HDL设计中对目标的位数进行了设定,如:reg[4:0] a;而默认为32位,将位数裁定到合适的大小 措施:如果结果正确,无须加以修正,如果不想看到这个警告,可以改变设定的位数
3.All reachable assignments to data_out(10) assign ‘0‘, register removed by optimization 原因:经过综合器优化后，输出端口已经不起作用了
4.Following 9 pins have nothing, GND, or VCC driving datain port -- changes to this connectivity may change fitting results
原因:第9脚，空或接地或接上了电源 措施:有时候定义了输出端口，但输出端直接赋‘0’，便会被接地，赋‘1’接电源。如果你的设计中这些端口就是这样用的，那便可以不理会这些warning
5.Found pins functioning as undefined clocks and/or memory enables
原因:是你作为时钟的PIN没有约束信息。可以对相应的PIN做一下设定就行了。主要是指你的某些管脚在电路当中起到了时钟管脚的 作用，比如flip-flop的clk管脚，而此管脚没有时钟约束，因此QuartusII把“clk”作为未定义的时钟。
措施:如果clk不是时钟，可以加“not clock”的约束；如果是，可以在clock setting当中加入；在某些对时钟要求不很高的情况下，可以忽略此警告或在这里修改:Assignments>Timing analysis settings...>Individual clocks...>... 注意在Applies to node中只用选择时钟引脚一项即可，required fmax一般比所要求频率高5%即可，无须太紧或太松。
6.Timing characteristics of device EPM570T144C5 are preliminary
原因:因为MAXII 是比較新的元件在 QuartusII 中的時序並不是正式版的,要等 Service Pack 措施:只影响 Quartus 的 Waveform
7.Warning: Clock latency analysis for PLL offsets is supported for the current device family, but is not enabled
措施:将setting中的timing Requirements&Option-->More Timing Setting-->setting-->Enable Clock Latency中的on改成OFF
8.Found clock high time violation at 14.8 ns on register "|counter|lpm_counter:count1_rtl_0|dffs[11]"
原因:违反了steup/hold时间，应该是后仿真，看看波形设置是否和时钟沿符合steup/hold时间
措施:在中间加个寄存器可能可以解决问题
9.warning: circuit may not operate.detected 46 non-operational paths clocked by clock clk44 with clock skew larger than data delay
原因:时钟抖动大于数据延时,当时钟很快，而if等类的层次过多就会出现这种问题,但这个问题多是在器件的最高频率中才会出现
措施：setting-->timing Requirements&Options-->Default required fmax 改小一些，如改到50MHZ
10.Design contains <number> input pin(s) that do not drive logic
原因:输入引脚没有驱动逻辑(驱动其他引脚）,所有的输入引脚需要有输入逻辑
措施:如果这种情况是故意的,无须理会,如果非故意,输入逻辑驱动.
11.Warning：Found clock high time violation at 8.9ns on node ‘TEST3.CLK‘
原因：FF中输入的PLS的保持时间过短
措施：在FF中设置较高的时钟频率
12.Warning: Found 10 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew
原因:如果你用的 CPLD 只有一组全局时钟时，用全局时钟分频产生的另一个时钟在布线中当作信号处理，不能保证低的时钟歪斜(SKEW)。会造成在这个时钟上工作的时序电路不可靠，甚至每次布线产生的问题都不一样。
措施:如果用有两组以上全局时钟的 FPGA 芯片，可以把第二个全局时钟作为另一个时钟用，可以解决这个问题。
13.Critical Warning: Timing requirements were not met. See Report window for details.
原因：时序要求未满足，
措施：双击Compilation Report-->Time Analyzer-->红色部分（如clock setup:‘clk‘等）-->左键单击list path,查看fmax的SLACK REPORT再根据提示解决,有可能是程序的算法问题或fmax设置问题
14.Warning: Can‘t find signal in vector source file for input pin |whole|clk10m
原因：这个时因为你的波形仿真文件（ vector source file ）中并没有把所有的输入信号(input pin)加进去，对于每一个输入都需要有激励源的
15.Can‘t achieve minimum setup and hold requirement <text> along <number> path(s). See Report window for details.
原因：时序分析发现一定数量的路径违背了最小的建立和保持时间，与时钟歪斜有关,一般是由于多时钟引起的
措施：利用Compilation Report-->Time Analyzer-->红色部分（如clock hold:‘clk‘等），在slack中观察是hold time为负值还是setup time 为负值，然后在：Assignment-->Assignment Editor-->To中增加时钟名(from node finder)，Assignment Name中增加和多时钟有关的Multicycle 和Multicycle Hold选项，如hold time为负，可使Multicycle hold的值>multicycle,如设为2和1。
16: Can‘t analyze file -- file E://quartusii/*/*.v is missing
原因：试图编译一个不存在的文件，该文件可能被改名或者删除了
措施：不管他，没什么影响
17.Warning: Can‘t find signal in vector source file for input pin |whole|clk10m
原因：因为你的波形仿真文件（ vector source file ）中并没有把所有的输入信号(input pin)加进去，对于每一个输入都需要有激励源的
18.Error: Can‘t name logic function scfifo0 of instance "inst" -- function has same name as current design file
原因：模块的名字和project的名字重名了
措施：把两个名字之一改一下，一般改模块的名字
19.Warning: Using design file lpm_fifo0.v, which is not specified as a design file for the current project, but contains definitions for 1 design units and 1 entities in project Info: Found entity 1: lpm_fifo0
原因：模块不是在本项目生成的，而是直接copy了别的项目的原理图和源程序而生成的，而不是用QUARTUS将文件添加进本项目
措施：无须理会，不影响使用
20.Timing characteristics of device <name> are preliminary
原因：目前版本的QuartusII只对该器件提供初步的时序特征分析
措施：如果坚持用目前的器件，无须理会该警告。关于进一步的时序特征分析会在后续版本的Quartus得到完善。
21.Timing Analysis does not support the analysis of latches as synchronous elements for the currently selected device family
原因：用analyze_latches_as_synchronous_elements setting可以让Quaruts II来分析同步锁存，但目前的器件不支持这个特性
措施：无须理会。时序分析可能将锁存器分析成回路。但并不一定分析正确。其后果可能会导致显示提醒用户：改变设计来消除锁存器,但实际其实无关紧要
22.Warning:Found xx 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
Quartus常见错误分析 Error
1 Warning: VHDL Process Statement warning at random.vhd(18): signal reset is in statement, but is not in sensitivity list
----没把singal放到process（）中
2 Warning: Found pins ing as undefined clocks and/or memory enables
Info: Assuming node CLK is an undefined clock
-=-----可能是说设计中产生的触发器没有使能端
3 Error: VHDL Interface Declaration error in clk_gen.vhd(29): interface object "clk_scan" of mode out cannot be read. Change object mode to buffer or inout.
------信号类型设置不对，out当作buffer来定义
4 Error: Node instance "clk_gen1" instantiates undefined entity "clk_gen"
-------引用的例化元件未定义实体－－entity "clk_gen"
5 Warning: Found 2 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew
Info: Detected ripple clock "clk_gen:clk_gen1|clk_incr" as buffer
Info: Detected ripple clock "clk_gen:clk_gen1|clk_scan" as buffer
6 Warning: VHDL Process Statement warning at ledmux.vhd(15): signal or variable "dataout" may not be assigned a new in every possible path through the Process Statement. Signal or variable "dataout" holds its previous in every path with no new assignment, which may create a combinational loop in the current design.
7 Warning: VHDL Process Statement warning at divider_10.vhd(17): signal "cnt" is read inside the Process Statement but isn‘t in the Process Statement‘s sensivitity list
-----缺少敏感信号
8 Warning: No clock transition on "counter_bcd7:counter_counter_clk|q_sig[3]" register
9 Warning: Reduced register "counter_bcd7:counter_counter_clk|q_sig[3]" with stuck clock port to stuck GND
10 Warning: Circuit may not operate. Detected 1 non-operational path(s) clocked by clock "class[1]" with clock skew larger than data delay. See Compilation Report for details.
11 Warning: Circuit may not operate. Detected 1 non-operational path(s) clocked by clock "sign" with clock skew larger than data delay. See Compilation Report for details.
12 Error: VHDL error at counter_clk.vhd(90): actual port "class" of mode "in" cannot be associated with formal port "class" of mode "out"
------两者不能连接起来
13 Warning: Ignored node in vector source file. Can‘t find corresponding node name "class_sig[2]" in design.
------没有编写testbench文件，或者没有编辑输入变量的值 testbench里是元件申明和映射
14 Error: VHDL Binding Indication error at freqdetect_top.vhd(19): port "class" in design entity does not have std_logic_vector type that is specified for the same generic in the associated component
---在相关的元件里没有当前文件所定义的类型
15 Error: VHDL error at tongbu.vhd(16): can‘t infer register for signal "gate" because signal does not hold its outside clock edge
16 Warning: Found clock high time violation at 1000.0 ns on register
"|fcounter|lpm_counter:temp_rtl_0|dffs[4]"
17 Warning: Compiler packed, optimized or synthesized away node "temp[19]". Ignored vector source file node.
---"temp[19]"被优化掉了
18 Warning: Reduced register "gate~reg0" with stuck data_in port to stuck GND
19 Warning: Design contains 2 input pin(s) that do not drive logic
Warning: No output dependent on input pin "clk"
Warning: No output dependent on input pin "sign"
------输出信号与输入信号无关，
20 Warning: Found clock high time violation at 16625.0 ns on register "|impulcomp|gate1"
21 Error: VHDL error at impulcomp.vhd(19): can‘t implement clock enable condition specified using binary operator "or"
22 Error: VHDL Association List error at period_counter.vhd(38): actual parameter assigned to formal parameter "alarm", but formal parameter is not declared
-------连接表错误，形参"alarm"赋值给实参，形参没定义，可能是形参与实参的位置颠倒了，规定形参在实参之前。
23 Error: Ignored construct behavier at period_counter.vhd(15) because of previous errors
－－－－－－－－因为前一个错误而导致的错误
24 Error: VHDL error at period_counter.vhd(38): type of identifier "alarm" does not agree with its usage as std_logic type
－－－－－－－－"alarm"的定义类型与使用的类型不一致
25 Error: VHDL error at shift_reg.vhd(24): can‘t synthesize logic for statement with conditions that test for the edges of multiple clocks
-------同一进程中含有两个或多个if(edge)条件，（一个进程中之能有一个时钟沿）
26 Error: Can‘t resolve multiple constant drivers for net "datain_reg[22]" at shift_reg.vhd(19)
27 can‘t infer register for signal "num[0]" because signal does not hold its outside clock edge
28Error: Can‘t elaborate top-level user hierarchy
29 Error: Can‘t resolve multiple constant drivers for net "cs_in" at led_key.vhd(32) ----------有两
个以上赋值语句，不能确定“cs_in”的值，
30 Warning: Ignored node in vector source file. Can‘t find corresponding node name "over" in design.
---------------在源文件中找不到对应的节点“over”。
31 Error: Can‘t access JTAG chain
无法找到下载链
32 Info: Assuming node "clk" is an undefined clock
Quartus警告分析 Warning
1.Found clock-sensitive change during active clock edge at time <time> on register "<name>"
原因：vector source file中时钟敏感信号（如：数据，允许端，清零，同步加载等）在时钟的边缘同时变化。而时钟敏感信号是不能在时钟边沿变化的。其后果为导致结果不正确。
措施：编辑vector source file
2.Verilog HDL assignment warning at <location>: truncated with size <number> to match size of target (<number>
原因:在HDL设计中对目标的位数进行了设定,如:reg[4:0] a;而默认为32位, 将位数裁定到合适的大小
措施:如果结果正确,无须加以修正,如果不想看到这个警告,可以改变设定的位数
3.All reachable assignments to data_out(10) assign ‘0‘, register removed by optimization
原因:经过综合器优化后，输出端口已经不起作用了
4.Following 9 pins have nothing, GND, or VCC driving datain port -- changes to this connectivity may change fitting results
原因:第9脚，空或接地或接上了电源
措施:有时候定义了输出端口，但输出端直接赋‘0’，便会被接地，赋‘1’接电源。
如果你的设计中这些端口就是这样用的，那便可以不理会这些warning
5.Found pins ing as undefined clocks and/or memory enables
原因:是你作为时钟的PIN没有约束信息。可以对相应的PIN做一下设定就行了。
主要是指你的某些管脚在电路当中起到了时钟管脚的作用，比如flip-flop的clk管脚，而此管脚没有时钟约束，因此QuartusII把“clk”作为未定义的时钟。
措施:如果clk不是时钟，可以加“not clock”的约束；如果是，可以在clock setting当中加入；在某些对时钟要求不很高的情况下，可以忽略此警告或在这里修改:Assignments>Timing analysis settings...>Individual clocks...>...
6.Timing characteristics of device EPM570T144C5 are preliminary
原因:因为MAXII 是比較新的元件在 QuartusII 中的時序并不是正式版的,要等 Service Pack
措施:只影响 Quartus 的 Waveform
7.Warning: Clock latency analysis for PLL offsets is supported for the current device family, but is not enabled
措施:将setting中的timing Requirements&Option-->More Timing Setting-->setting-->Enable Clock Latency中的on改成OFF
8.Found clock high time violation at 14.8 ns on register "|counter|lpm_counter:count1_rtl_0|dffs[11]"
原因:违反了steup/hold时间，应该是后仿真，看看波形设置是否和时钟沿符合steup/hold时间
措施:在中间加个寄存器可能可以解决问题
9.warning: circuit may not operate.detected 46 non-operational paths clocked by clock clk44 with clock skew larger than data delay
原因:时钟抖动大于数据延时,当时钟很快，而if等类的层次过多就会出现这种问题,但这个问题多是在器件的最高频率中才会出现
措施：setting-->timing Requirements&Options-->Default required fmax 改小一些，如改到50MHZ
10.Design contains <number> input pin(s) that do not drive logic
原因:输入引脚没有驱动逻辑(驱动其他引脚）,所有的输入引脚需要有输入逻辑
措施:如果这种情况是故意的,无须理会,如果非故意,输入逻辑驱动
11.Warning：Found clock high time violation at 8.9ns on node ‘TEST3.CLK‘
原因：FF中输入的PLS的保持时间过短
措施：在FF中设置较高的时钟频率
12.Warning: Found 10 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew
原因:如果你用的 CPLD 只有一组全局时钟时，用全局时钟分频产生的另一个时钟在布线中当作信号处理，不能保证低的时钟歪斜(SKEW)。会造成在这个时钟上工作的时序电路不可靠，甚至每次布线产生的问题都不一样。
措施:如果用有两组以上全局时钟的 FPGA 芯片，可以把第二个全局时钟作为另一个时钟用，可以解决这个问题。
13.Critical Warning: Timing requirements were not met. See Report window for details.
原因：时序要求未满足
措施：双击Compilation Report-->Time Analyzer-->红色部分（如clock setup:‘clk‘等）-->左键单击list path,查看fmax的SLACK REPORT再根据提示解决,有可能是程序的算法问题
14.Can‘t achieve minimum setup and hold requirement <text> along <number> path(s). See Report window for details.
原因：时序分析发现一定数量的路径违背了最小的建立和保持时间，与时钟歪斜有关,一般是由于多时钟引起的
措施：利用Compilation Report-->Time Analyzer-->红色部分（如clockhold:‘clk‘等），在slack中观察是hold time为负值还是setup time 为负值，然后在：Assignment-->Assignment Editor-->To中增加时钟名(from node finder)，Assignment Name中增加和多时钟有关的Multicycle 和Multicycle Hold选项，如hold time为负，可使Multicycle hold的值>multicycle,如设为2和1。
15: Can‘t analyze file -- file E://quartusii/*/*.v is missing
原因：试图编译一个不存在的文件，该文件可能被改名或者删除了
措施：不管他，没什么影响
16.Warning: Can‘t find signal in vector source file for input pin |whole|clk10m
原因：因为你的波形仿真文件（ vector source file ）中并没有把所有的输入信号(input pin)加进去，对于每一个输入都需要有激励源的
17.Error: Can‘t name logic scfifo0 of instance "inst" -- has same name as current design file
原因：模块的名字和project的名字重名了
措施：把两个名字之一改一下，一般改模块的名字
18.Warning: Using design file lpm_fifo0.v, which is not specified as a design file for the current project, but contains definitions for 1 design units and 1 entities in project Info: Found entity 1: lpm_fifo0
原因：模块不是在本项目生成的，而是直接copy了别的项目的原理图和源程序而生成的，而不是用QUARTUS将文件添加进本项目
措施：无须理会，不影响使用
19.Timing characteristics of device <name> are preliminary
原因：目前版本的QuartusII只对该器件提供初步的时序特征分析
措施：如果坚持用目前的器件，无须理会该警告。关于进一步的时序特征分析会在后续版本的Quartus得到完善。
20.Timing Analysis does not support the analysis of latches as synchronous elements for the currently selected device family
原因：用analyze_latches_as_synchronous_elements setting可以让Quaruts II来分析同步锁存，但目前的器件不支持这个特性
措施：无须理会。时序分析可能将锁存器分析成回路。但并不一定分析正确。其后果可能会导致显示提醒用户：改变设计来消除锁 存器
21.Warning:Found xx output pins without output pin load capacitanceassignment（网友：gucheng82提供）
原因：没有给输出管教指定负载电容
措施：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
22.Warning: Found 6 node(s) in clock paths which may be acting asripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting inclock skew
原因：使用了行波时钟或门控时钟，把触发器的输出当时钟用就会报行波时钟，将组合逻辑的输出当时钟用就会报门控时钟
措施：不要把触发器的输出当时钟，不要将组合逻辑的输出当时钟，如果本身如此设计，则无须理会该警告
23.Warning (10268): Verilog HDL information at lcd7106.v(63):Always Construct contains both blocking and non-blocking assignments
原因： 一个always模块中同时有阻塞和非阻塞的赋值
原文地址：https://www.cnblogs.com/schips/p/10042297.html