1.Found clock-sensitive change during active clock edge at time <time> on register "<name>" 原因:vector source file中時鐘敏感信號(如:數(shù)據(jù),允許端,清零,同步加載等)在時鐘的邊緣同時變化。而時鐘敏感信號是不能在時鐘邊沿變化的。其后果為導(dǎo)致結(jié)果不正確。 措施:編輯vector source file 2.Verilog HDL assignment warning at <location>: truncated with size <number> to match size of target (<number> 原因:在HDL設(shè)計中對目標(biāo)的位數(shù)進(jìn)行了設(shè)定,如:reg[4:0] a;而默認(rèn)為32位,將位數(shù)裁定到合適的大小 措施:如果結(jié)果正確,無須加以修正,如果不想看到這個警告,可以改變設(shè)定的位數(shù) 3.All reachable assignments to data_out(10) assign '0', register removed by optimization 原因:經(jīng)過綜合器優(yōu)化后,輸出端口已經(jīng)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腳,空或接地或接上了電源 措施:有時候定義了輸出端口,但輸出端直接賦‘0’,便會被接地,賦‘1’接電源。 如果你的設(shè)計中這些端口就是這樣用的,那便可以不理會這些warning 5.Found pins ing as undefined clocks and/or memory enables 原因:是你作為時鐘的PIN沒有約束信息?梢詫ο鄳(yīng)的PIN做一下設(shè)定就行了。主要是指你的某些管腳在電路當(dāng)中起到了時鐘管腳的作用,比如flip-flop的clk管腳,而此管腳沒有時鐘約束,因此QuartusII把“clk”作為未定義的時鐘。 措施:如果clk不是時鐘,可以加“not clock”的約束;如果是,可以在clock setting當(dāng)中加入;在某些對時鐘要求不很高的情況下,可以忽略此警告或在這里修改:Assignments>Timing analysis settings...>Individual clocks...>... 6.Timing characteristics of device EPM570T144C5 are preliminary 原因:因為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:只影響 Quartus 的 Waveform 7.Warning: Clock latency analysis for PLL offsets is supported for the current device family, but is not enabled 措施:將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:違反了steup/hold時間,應(yīng)該是后仿真,看看波形設(shè)置是否和時鐘沿符合steup/hold時間 措施:在中間加個寄存器可能可以解決問題 9.warning: circuit may not operate.detected 46 non-operational paths clocked by clock clk44 with clock skew larger than data delay 原因:時鐘抖動大于數(shù)據(jù)延時,當(dāng)時鐘很快,而if等類的層次過多就會出現(xiàn)這種問題,但這個問題多是在器件的最高頻率中才會出現(xiàn) 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:輸入引腳沒有驅(qū)動邏輯(驅(qū)動其他引腳),所有的輸入引腳需要有輸入邏輯 措施:如果這種情況是故意的,無須理會,如果非故意,輸入邏輯驅(qū)動. 11.Warning:Found clock high time violation at 8.9ns on node 'TEST3.CLK' 原因:FF中輸入的PLS的保持時間過短 措施:在FF中設(shè)置較高的時鐘頻率 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 只有一組全局時鐘時,用全局時鐘分頻產(chǎn)生的另一個時鐘在布線中當(dāng)作信號處理,不能保證低的時鐘歪斜(SKEW)。會造成在這個時鐘上工作的時序電路不可靠,甚至每次布線產(chǎn)生的問題都不一樣。 措施:如果用有兩組以上全局時鐘的 FPGA 芯片,可以把第二個全局時鐘作為另一個時鐘用,可以解決這個問題。 13.Critical Warning: Timing requirements were not met. See Report window for details. 原因:時序要求未滿足, 措施:雙擊Compilation Report-->Time Analyzer-->紅色部分(如clock setup:'clk'等)-->左鍵單擊list path,查看fmax的SLACK REPORT再根據(jù)提示解決,有可能是程序的算法問題 14.Can't achieve minimum setup and hold requirement <text> along <number> path(s). See Report window for details. 原因:時序分析發(fā)現(xiàn)一定數(shù)量的路徑違背了最小的建立和保持時間,與時鐘歪斜有關(guān),一般是由于多時鐘引起的 措施:利用Compilation Report-->Time Analyzer-->紅色部分(如clock hold:'clk'等),在slack中觀察是hold time為負(fù)值還是setup time 為負(fù)值,然后在:Assignment-->Assignment Editor-->To中增加時鐘名(from node finder),Assignment Name中增加 多時鐘有關(guān)的Multicycle 和Multicycle Hold選項,如hold time為負(fù),可使Multicycle hold的值>multicycle,如設(shè)為2和1。 15: Can't analyze file -- file E://quartusii/*/*.v is missing 原因:試圖編譯一個不存在的文件,該文件可能被改名或者刪除了 措施:不管他,沒什么影響 16.Warning: Can't find signal in vector source file for input pin |whole|clk10m 原因:因為你的波形仿真文件( vector source file )中并沒有把所有的輸入 信號(input pin)加進(jìn)去,對于每一個輸入都需要有激勵源的 17.Error: Can't name logic scfifo0 of instance "inst" -- has same name as current design file 原因:模塊的名字和project的名字重名了 措施:把兩個名字之一改一下,一般改模塊的名字 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:模塊不是在本項目生成的,而是直接copy了別的項目的原理圖和源程序而生成的,而不是用QUARTUS將文件添加進(jìn)本項目 措施:無須理會,不影響使用 19.Timing characteristics of device <name> are preliminary 原因:目前版本的QuartusII只對該器件提供初步的時序特征分析 措施:如果堅持用目前的器件,無須理會該警告。關(guān)于進(jìn)一步的時序特征分析會在后續(xù)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可以讓Quaruts II來分析同步鎖存,但目前的器件不支持這個特性 措施:無須理會。時序分析可能將鎖存器分析成回路。但并不一定分析正確。其后果可能會導(dǎo)致顯示提醒用戶:改變設(shè)計來消除鎖 存器 21.Warning:Found xx output pins without output pin load capacitance assignment(網(wǎng)友:gucheng82提供) 原因:沒有給輸出管教指定負(fù)載電容 措施:該功能用于估算TCO和功耗,可以不理會,也可以在Assignment Editor中為相應(yīng)的輸出管腳指定負(fù)載電容,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:使用了行波時鐘或門控時鐘,把觸發(fā)器的輸出當(dāng)時鐘用就會報行波時鐘,將組合邏輯的輸出當(dāng)時鐘用就會報門控時鐘 措施:不要把觸發(fā)器的輸出當(dāng)時鐘,不要將組合邏輯的輸出當(dāng)時鐘,如果本身如此設(shè)計,則無須理會該警告 23.Warning (10268): Verilog HDL information at lcd7106.v(63): Always Construct contains both blocking and non-blocking assignments 原因: 一個always模塊中同時有阻塞和非阻塞的賦值 1Warning: VHDL Process Statement warning at random.vhd(18): signal reset is in statement, but is not in sensitivity list ----沒把singal放到process()中 2 Warning: Found pins ing as undefined clocks and/or memory enablesInfo: Assuming node CLK is an undefined clock -=-----可能是說設(shè)計中產(chǎn)生的觸發(fā)器沒有使能端 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. ------信號類型設(shè)置不對,out當(dāng)作buffer來定義 4 Error: Node instance "clk_gen1" instantiates undefined entity "clk_gen" -------引用的例化元件未定義實體--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 -----缺少敏感信號 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" ------兩者不能連接起來 13 Warning: Ignored node in vector source file. Can't find corresponding node name "class_sig[2]" in design. ------沒有編寫testbench文件,或者沒有編輯輸入變量的值 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 ---在相關(guān)的元件里沒有當(dāng)前文件所定義的類型 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]"被優(yōu)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" ------輸出信號與輸入信號無關(guān), 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 -------連接表錯誤,形參"alarm"賦值給實參,形參沒定義,可能是形參與實參的位置顛倒了,規(guī)定形參在實參之前。 23 Error: Ignored construct behavier at period_counter.vhd(15) because of previous errors 。驗榍耙粋錯誤而導(dǎo)致的錯誤 24 Error: VHDL error at period_counter.vhd(38): type of identifier "alarm" does not agree with its usage as std_logic type --------"alarm"的定義類型與使用的類型不一致 warning: Info: Pin num[0] not assigned to an exact location on the device num[0]管腳沒有在器件上非配一個準(zhǔn)確位置 解決方法:進(jìn)行管腳分配。 Warning: Found pins functioning as undefined clocks and/or memory enables Info: Assuming node "clk" is an undefined clock 原因:是你作為時鐘的PIN沒有約束信息?梢詫ο鄳(yīng)的PIN做一下設(shè)定就行了。主要是指你的某些管腳在電路當(dāng)中起到了時鐘管腳的作用,比如flip-flop的clk管腳,而此管腳沒有時鐘約束,因此QuartusII把“clk”作為未定義的時鐘。 措施:如果clk不是時鐘,可以加“not clock”的約束;如果是,可以在clock setting當(dāng)中加入;在某些對時鐘要求不很高的情況下,可以忽略此警告或在這里修改:Assignments>Timing analysis settings...>Individualclocks...>... 注意在Applies to node中只用選擇時鐘引腳一項即可,required fmax一般比所要求頻率高5%即可,無須太緊或太松。 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 -------同一進(jìn)程中含有兩個或多個if(edge)條件,(一個進(jìn)程中之能有一個時鐘沿) 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) ----------有兩個以上賦值語句,不能確定“cs_in”的值, 30 Warning: Ignored node in vector source file. Can't find corresponding node name "over" in design. ---------------在源文件中找不到對應(yīng)的節(jié)點“over”。 31 Error: Can't access JTAG chain 無法找到下載鏈 Warning (10541)的意思是設(shè)計中使用了一個未賦值的信號,并且沒有復(fù)位值,這樣該信號為無效值(確定但不可知),被其他邏輯使用也許會導(dǎo)致錯誤。 Warning (10036)不用管它,大概是說有個信號未被使用,這樣不會對邏輯產(chǎn)生任何影響,當(dāng)然也可以考慮刪除它。 Warning (10492)是很常見的,這個關(guān)系到編碼風(fēng)格問題。在process里作為被判斷信號(if或者case后面的)或者賦值語句右端信號通常應(yīng)該寫在process的敏感信號表里。有些eda工具不檢查這個,可能會導(dǎo)致仿真結(jié)果與綜合出來的電路不一致。實際上,綜合工具在綜合的時候會自動把這類信號添加到敏感信號表里,但仿真工具不會,而是完全按照代碼體現(xiàn)的語意來仿真。 Reduced register ...這兩個應(yīng)該是說明eda工具所作的優(yōu)化,去掉了一些多余的D觸發(fā)器。 Output pins are stuck at VCC or GND 如果正是希望某些輸出被固定置高電平或低電平或者無所謂,就不用管它,否則請檢查代碼。 Design contains 1 input pin(s) that do not drive logic 這個也比較常見,eda工具會提醒設(shè)計中沒被用到的輸入,然而這經(jīng)常就是設(shè)計者的本意(不關(guān)心某些輸入)。 Found 1 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 這就是說明門控時鐘帶來的扭曲
1.Found clock-sensitive change during active clock edge at time <time> on register "<name>" 原因:vector source file中時鐘敏感信號(如:數(shù)據(jù),允許端,清零,同步加載等)在時鐘的邊緣同時變化。而時鐘敏感信號是 不能在時鐘邊沿變化的。其后果為導(dǎo)致結(jié)果不正確。 措施:編輯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設(shè)計中對目標(biāo)的位數(shù)進(jìn)行了設(shè)定,如:reg[4:0] a;而默認(rèn)為32位,將位數(shù)裁定到合適的大小 措施:如果結(jié)果正確,無須加以修正,如果不想看到這個警告,可以改變設(shè)定的位數(shù) 3.All reachable assignments to data_out(10) assign '0', register removed by optimization 原因:經(jīng)過綜合器優(yōu)化后,輸出端口已經(jīng)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腳,空或接地或接上了電源 措施:有時候定義了輸出端口,但輸出端直接賦‘0’,便會被接地,賦‘1’接電源。如果你的設(shè)計中這些端口就是這樣用的,那便可以不理會這些warning 5.Found pins functioning as undefined clocks and/or memory enables 原因:是你作為時鐘的PIN沒有約束信息。可以對相應(yīng)的PIN做一下設(shè)定就行了。主要是指你的某些管腳在電路當(dāng)中起到了時鐘管腳的 作用,比如flip-flop的clk管腳,而此管腳沒有時鐘約束,因此QuartusII把“clk”作為未定義的時鐘。 措施:如果clk不是時鐘,可以加“not clock”的約束;如果是,可以在clock setting當(dāng)中加入;在某些對時鐘要求不很高的情況下,可以忽略此警告或在這里修改:Assignments>Timing analysis settings...>Individual clocks...>... 6.Timing characteristics of device EPM570T144C5 are preliminary 原因:因為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:只影響 Quartus 的 Waveform 7.Warning: Clock latency analysis for PLL offsets is supported for the current device family, but is not enabled 措施:將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:違反了steup/hold時間,應(yīng)該是后仿真,看看波形設(shè)置是否和時鐘沿符合steup/hold時間 措施:在中間加個寄存器可能可以解決問題 9.warning: circuit may not operate.detected 46 non-operational paths clocked by clock clk44 with clock skew larger than data delay 原因:時鐘抖動大于數(shù)據(jù)延時,當(dāng)時鐘很快,而if等類的層次過多就會出現(xiàn)這種問題,但這個問題多是在器件的最高頻率中才會出現(xiàn) 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:輸入引腳沒有驅(qū)動邏輯(驅(qū)動其他引腳),所有的輸入引腳需要有輸入邏輯 措施:如果這種情況是故意的,無須理會,如果非故意,輸入邏輯驅(qū)動. 11.Warning:Found clock high time violation at 8.9ns on node 'TEST3.CLK' 原因:FF中輸入的PLS的保持時間過短 措施:在FF中設(shè)置較高的時鐘頻率 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 只有一組全局時鐘時,用全局時鐘分頻產(chǎn)生的另一個時鐘在布線中當(dāng)作信號處理,不能保證低的時鐘歪斜(SKEW)。會造成在這個時鐘上工作的時序電路不可靠,甚至每次布線產(chǎn)生的問題都不一樣。 措施:如果用有兩組以上全局時鐘的 FPGA 芯片,可以把第二個全局時鐘作為另一個時鐘用,可以解決這個問題。 第5條補(bǔ)充如下: 5.Found pins functioning as undefined clocks and/or memory enables ......可以忽略此警告 Assignments>Timing analysis settings...>Individual clocks...>... new Clock setting-->注意在Applies to node中只用選擇時鐘引腳一項即可,required fmax一般比所要求頻率高5%即可,無須太緊或太松。 增加第13條: 13.Critical Warning: Timing requirements were not met. See Report window for details. 原因:時序要求未滿足, 措施:雙擊Compilation Report-->Time Analyzer-->紅色部分(如clock setup:'clk'等)-->左鍵單擊list path,查看fmax的SLACK REPORT再根據(jù)提示解決,有可能是程序的算法問題或fmax設(shè)置問題 ps:大家如果有什么難解決的warning也可以發(fā)上來討論一下,如果有已經(jīng)解決的疑難warning解決方法,也可以一起分享經(jīng)驗.上面的情況如有錯誤之處,歡迎拍磚 14.Can't achieve minimum setup and hold requirement <text> along <number> path(s). See Report window for details. 原因:時序分析發(fā)現(xiàn)一定數(shù)量的路徑違背了最小的建立和保持時間,與時鐘歪斜有關(guān),一般是由于多時鐘引起的 措施:利用Compilation Report-->Time Analyzer-->紅色部分(如clock hold:'clk'等),在slack中觀察是hold time為負(fù)值還是setup time 為負(fù)值,然后在:Assignment-->Assignment Editor-->To中增加時鐘名(from node finder),Assignment Name中增加和多時鐘有關(guān)的Multicycle 和Multicycle Hold選項,如hold time為負(fù),可使Multicycle hold的值>multicycle,如設(shè)為2和1。 15: Can't analyze file -- file E://quartusii/*/*.v is missing 原因:試圖編譯一個不存在的文件,該文件可能被改名或者刪除了措施:不管他,沒什么影響 16.Warning: Can't find signal in vector source file for input pin |whole|clk10m 原因:因為你的波形仿真文件( vector source file )中并沒有把所有的輸入信號(input pin)加進(jìn)去, 對于每一個輸入都需要有激勵源的 17.Error: Can't name logic function scfifo0 of instance "inst" -- function has same name as current design file 原因:模塊的名字和project的名字重名了 措施:把兩個名字之一改一下,一般改模塊的名字
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