在QuartusII下进行编译和仿真的时候,会出现一堆warning,有的可以忽略,有的却需要注意,虽然按F1可以了解关于该警告的帮助,但有时候帮助解释的仍然不清楚,大家群策群力,把自己知道和了解的一些关于警告的问题都说出来讨论一下,免得后来的人走弯路.
下面是我收集整理的一些,有些是自己的经验,有些是网友的,希望能给大家一点帮助,如有不对的地方,请指正,如果觉得好,请版主给点威望吧,谢谢
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 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。FPGA
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
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
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(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 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
用户239537 2009-12-18 22:19