Язык Dot для Автогенерации Блок Схем Сложных Электронных Цепей

Современные печатные платы достигают очень высокого уровня сложности. Особенно трудно разобраться в логике цепей питания. Так же сложность добавляет тот факт, что схемотехника от вендора в *.pdf дискретная. На схеме есть летающие фрагменты.

Как же понять и разобраться в новой схемотехнике очередной навороченной платы?

Как понять с какой стороны подходить к печатной плате?

Как понять куда подавать питание, куда подключать программатор, а куда отладочный UART?

Чтобы ответить на все эти вопросы надо четко себе представлять схему платы на системном уровне. Нужен Helicopter View или проще говоря подробная блок схема устройства.

Как же создать блок-схему сложнецкой платы? Как не ошибиться с разводкой топологии?

Любая принципиальная схема это, в сущности, граф. Набор вершин и ребер. Это значит, что схемотехнику можно представить языком разметки графов. Таким языком является язык Dot. Далее соответствующим софтом автоматически развести граф.

Проделаем этот путь на примере всем известной отладочной платы nRF5340-DK.

Вот Dot код описывающий плату nRF5340-DK. Dot язык очень простой и код пишется прямо по схемотехнике из *.pdf

digraph graphname {  rankdir=LR;  ranksep=0.5;  IF_OFF[shape="point"][color=darkgreen]  VBUS[shape="point"]  USB2[shape="point"]  USB3[shape="point"]  RESET[shape="point"]  VDD_nRF_SENSE[shape="point"]  TRACE[shape="point"]  VDD_nRF_DASH[shape="point"]  I2C[shape="point"]  SWD[shape="point"][color=blue]  IMCU_RESET[shape="point"]  SWD0[shape="point"][color=blue]  SWD3[shape="point"][color=blue]  UART_1[shape="point"][color=magenta]  UART_2[shape="point"][color=magenta]  VBOOST_SRC[shape="point"]  GND[shape="point"]  VREG[shape="point"]  BOOT_RESET[shape="point"]  VREG_EN_INV[shape="point"]  VEXT_EN[shape="point"]  VSENSE_SW_OUT[shape="point"]  VSUPPLY[shape="point"]  VEXT_EN_INV[shape="point"] VBOOST_SRC_DASH[shape="point"]  VBUS_IMCU[shape="point"] V5V[shape="point"] VDD[shape="point"][fillcolor=grey, style=red]  J1[shape="box",label="J1 ANT 1pin "]     U1[shape="box"][label="U1 MCU"][fillcolor=grey, style=filled][height=8] [width=3]  U2[shape="box"][fillcolor=grey, style=filled][height=4][width=3][label="U2 If MCU"] J2[shape="box",label="J2 5pin"][height=2][width=1] J3[shape="box",label="J3 USB 5pin"][height=2][width=1] J4[shape="box",label="J4 10pin"][height=3][width=1] J5[shape="box",label="J5 NFC 5pin"][height=2][width=1] J6[shape="box",label="J6 Li-Po 2pin"][height=1][width=1] P1[shape="box",label="P1 8pin"][height=2][width=1] P2[shape="box",label="P2 6pin"][height=1.5][width=1] P3[shape="box",label="P3 8pin"][height=2][width=1] P4[shape="box",label="P4 10pin"][height=3][width=1] P5[shape="box",label="P5 6pin"][height=1.5][width=1] P6[shape="box",label="P6 8pin"][height=2][width=1] P7[shape="box",label="P7 16pin"][height=4] [width=1] P8[shape="box",label="P8 12pin"][height=3][width=1] P9[shape="box",label="P9 DebugOut 8pin"][height=2] P10[shape="box",label="P10 20pin"][height=5][width=1] P11[shape="box",label="P11 6pin"][height=2] [width=1] P12[shape="box",label="P12 16pin"][height=4] [width=1] P13[shape="box",label="P13 16pin"][height=4] [width=1] P14[shape="box",label="P14 12pin"][height=3] [width=1] P15[shape="box",label="P15 16pin"] [height=4] [width=1] P16[shape="box",label="P16 20pin"][height=5][width=1] P17[shape="box",label="P17 16pin"][height=4] [width=1] P18[shape="box",label="P18 DebugIN 10pin"][height=3][width=1] P19[shape="box",label="P19 DebugOUT 10pin"][height=3][width=1] P20[shape="box",label="P20 13pin"][height=3.25][width=1] P21[shape="box",label="P21 2pin"][height=1][width=1] P22[shape="box",label="P22 current 2pin"] [width=1] P23[shape="box",label="P23 2pin"][height=1][width=1] P24[shape="box",label="P24 20pin"][height=5][width=1] P25[shape="box",label="P25 Trace 20pin"][height=5][width=1] P26[shape="box",label="P26 13pin"][height=3.25][width=1] P27[shape="box",label="P27 Li-Po 2pin"][height=1][width=1]  D7[shape="triangle"]  U25_12[shape="box"][fillcolor=grey, style=filled]  U11[shape="box"][fillcolor=grey, style=filled]  U3_34[shape="box"][fillcolor=grey, style=filled]  Q10B[shape="box"]  U18[shape="box",label="U18 AND" ][fillcolor=grey, style=filled] P28[shape="box",label="P28 Op-amp 3pin"][height=0.75][width=1]  U10[shape="box"][fillcolor=grey, style=filled]  U21[shape="box"][fillcolor=grey, style=filled]  U24[shape="box"][fillcolor=grey, style=filled]   U4[label="U4 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U12[label="U12 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U13[label="U13 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U14[label="U14 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U15[label="U15 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U17[label="U17 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U20[label="U20 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U19[label="U19 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U22[label="U22 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U23[label="U23 4pin"][shape="box"][fillcolor=darkslategray1, style=filled]  U16[shape="box"][fillcolor=grey, style=filled]  U5[shape="box"][fillcolor=grey, style=filled]  SW7A[shape="box"][fillcolor=bisque, style=filled]  SW7B[shape="box"][fillcolor=bisque, style=filled]    D3[shape="triangle"]  D5[shape="triangle"]  D6[shape="triangle"]  U7[shape="box",label="U7 Flash"][fillcolor=grey, style=filled]  SW1[shape="box"][fillcolor=bisque, style=filled];  SW2[shape="box"][fillcolor=bisque, style=filled];  SW3[shape="box"][fillcolor=bisque, style=filled];  SW4[shape="box"][fillcolor=bisque, style=filled];  SW5[shape="box"][fillcolor=bisque, style=filled]  LED1[shape="box"];  LED2[shape="box"];  LED3[shape="box"];    Q10A[shape="box"];  Q10B[shape="box"];  LED4[shape="box"];    U19->U2[label="VDD_IMCU"]  SW1->U1[label="P0.23"]   SW2->U1[label="P0.24"]   SW3->U1[label="P0.08"]   IMCU_RESET->U2[label="IMCU_RESET"]   SW4->U1[label="P0.09"]   U2->U25_34->U1;  U2->U3_12->U1;  U7->U1[label="QSPI"]   U6_12->RESET  U1->P18  RESET->U1[label="RESET"]  RESET->P18[label="RESET"]   RESET->P19[label="RESET"]   RESET->P20[label="RESET"]   RESET->U1[label="RESET"]   RESET->P25[label="RESET"]   U2->U5->U1  U1->P2  U1->P8  U1->P14  SW5->BOOT_RESET  P8->P2->P14  VBUS_IMCU->U2 [label="VBUS_IMCU"]   Bat1->U17[label="VBAT"]   U17->Q10B  Q5B->SW6A[label="USB_DETECT"]   GND->SW6A  U1->P4  U1->P16  P4->P10->P16  U22->VBUS_IMCU  U1->P6  P12->P6->P17  U1->P3  U1->P9  U1->P12  P9->P3->P15  U2->SWD3->U5 [label="SWD3"] [color=blue]  U5->SWD [label="SWD"] [color=blue]  X3->U2[label="32MHz"]   U25_34->UART_1->U1[label="UART_1"][color=magenta]  U2->U25_34[label="VCOM_0"]  U1->P10  P7->P1->P13  U3_34->UART_2->U1[label="UART_2"][color=magenta]  IF_OFF->U3_34[label="IF_OFF"][color=darkgreen]  U2->U3_34[label="VCOM_2"]  J4->U2  U2->Q1  Q1->LED5  U2->U3_34->U1  VREG_EN_INV->U21[label="VREG_EN_INV"]   VEXT_EN_INV->U21[label="VEXT_EN_INV"]   Q10A->Q10B[label="Gate"]   VSUPPLY->U21[label="VSUPPLY"][color=pink]   U21->Q10A[label="Gate"]  SWD->U1[label="SWD"] [color=blue]  P18->SWD [label="SWD"] [color=blue]  J3->USB3->U1[label="USB"]   P19->SWD0->U2[label="SWD0"] [color=blue]  UART_1->P3[label="UART_1"] [color=magenta]  UART_2->P24[label="UART_2"] [color=magenta]  P1->RESET[label="RESET"]   J4->IMCU_RESET[label="IMCU_RESET"]  P11->P5  U1->P11  U1->P5  V5V->P13[label="V5V"][color=orange]   U1->P24  U1->P17  U1->P14  U1->P12  U1->P15  U1->I2C  I2C->P16 [label="I2C"]   J2->U22->U2  J2->Q5A  BOOT_RESET->U6_12[label="BOOT/RESET"]    U2->U6_12[label="IMCU_BOOT"]   SW8A->U6_34 [label="SHIELD_DETECT"]  I2C->U6_34 [label="I2C"]  SW8A->VDD[label="VDD"][color=red]  VDD->U6_34[label="VDD"][color=red]   Q5A[shape="box"]  Q5B[shape="box"]  //subgraph clusterQ5 { Q5A  Q5B }  X1->U1[label="32MHz"]   X2->U1[label="32kHz"]   U10->V5V  U1->J5[label="NFC"]   SW7A->U3_12[label="UART2_FC_OFF"] [color=green]  GND->SW7A  IF_OFF->SW7A[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  SW7B->U25_12[label="UART1_FC_OFF"] [color=green]  GND->SW7B  IF_OFF->SW7B[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  IF_OFF->U22[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  VBUS_IMCU->LED5[label="VBUS_IMCU"]  J4->VBUS->U22 [label="VBUS"][color=gold]  J2->VBUS->U22 [label="VBUS"][color=gold]  J2->USB2->U2[label="USB"]  GND->SW6B  SW9B->VDD->SW6B [label="VDD"][color=red]    //SW9B->Q10B[label="VDD"][color=red]   VDD->Q10B[label="VDD"][color=red]   U12->VSENSE_SW_OUT  U14->VSENSE_SW_OUT  Q10B->VSUPPLY  VSENSE_SW_OUT->SW8A[label="VSENSE_SW_OUT"]  U18->U17 [label="VBAT_EN"]   VSUPPLY->U14[label="VSUPPLY"][color=pink]  U13->VSUPPLY[label="VSUPPLY"][color=pink]   V5V->U12[label="V5V"][color=orange]   V5V->U11 [label="V5V"][color=orange]   U11->VREG[label="VREG"]   VREG->U13 [label="VREG"]   X1[fillcolor=yellow, style=filled]  X2[fillcolor=yellow, style=filled]  X3[fillcolor=yellow, style=filled]  LED1[fillcolor=green, style=filled]  LED2[fillcolor=green, style=filled]  LED3[fillcolor=green, style=filled]  LED4[fillcolor=green, style=filled]  LED5[fillcolor=green, style=filled]  U1->LED1[label="P0.28/AIN7"]  U1->LED2[label="P0.29"]  U1->LED3[label="P0.30"]  U1->LED4[label="P0.31"]  IF_OFF->U5[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  IF_OFF->U3_34[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  IF_OFF->U6_12[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  SW8A->U6_34[label="SHIELD_DETECT/VDD"]  IF_OFF->U25_34[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  U23->SW10B [label="VEXT"]  VSUPPLY->U23[label="VSUPPLY"][color=pink]  SW10B->P21  SW9A->SW10A[label="VSRC_NRF"]  U1->J1           U25_34[shape="box"][fillcolor=grey, style=filled]    U2->U25_12[label="VCOM0_CRTL"]  U25_12->U1[label="UART_1_CRTL"][color=magenta]    U2->U3_12[label="VCOM2_CRTL"]  U3_12->U1[label="UART_2_CRTL"][color=magenta]  SW8B->VBOOST_SRC     U9A[shape="box"][fillcolor=grey, style=filled]  U9B[shape="box"][fillcolor=grey, style=filled]  SW10A[shape="box"][fillcolor=bisque, style=filled];  SW10B[shape="box"][fillcolor=bisque, style=filled]; // subgraph clusterSW10 { SW10A SW10B }  VolDiv [label="1/2.74"] [shape="box"]      Bat1[label="Bat1 2pin"][shape="box"]   Q8A[shape="box"];  Q8B[shape="box"];  SW8A[shape="box"][fillcolor=bisque, style=filled];  SW8B[shape="box"][fillcolor=bisque, style=filled];  SW9A[shape="box"][fillcolor=bisque, style=filled];  SW9B[shape="box"][fillcolor=bisque, style=filled];      SW8B->Q6[label="Gate"]       U16->U13 [label="CTRL"]   SW6A[shape="box"][fillcolor=bisque, style=filled];  SW6B[shape="box"][fillcolor=bisque, style=filled];  VBOOST_SRC->U10  SW9B->U15[label="out"]  VDD->U15[label="VDD"][color=red]  VSUPPLY->U16[label="VSUPPLY"][color=pink]  VolDiv->U16[label="VREG_EN"]  U17->VSUPPLY->U18[label="VSUPPLY"][color=pink]  Q8A->VREG_EN_INV  VREG_EN_INV->U18[label="VREG_EN_INV"]  U24->VEXT_EN  VEXT_EN->Q8B [label="VEXT_EN"]   VEXT_EN->U23 [label="VEXT_EN"]   GND->Q5A    VDD_nRF_DASH->P20[label="VDD_nRF'"]  VDD_nRF_DASH->P26[label="VDD_nRF'"]  VDD_nRF_DASH->P22[label="VDD_nRF'"]  SW9A->VDD_nRF_DASH[label="VDD_nRF'"]  SW9A->VDD_nRF_SENSE[label="VDD_nRF_SENSE"]   VREG_EN_INV->U24[label="VREG_EN_INV"]     Q8B->VEXT_EN_INV  VEXT_EN_INV->U18[label="VEXT_EN_INV"]  SW6A->IF_OFF[color=darkgreen][fontcolor=darkgreen]  IF_OFF->U19[label="IF_OFF"][color=darkgreen][fontcolor=darkgreen]  VDD->U19[label="VDD"][color=red]    U15->P23[label="VDD_HV'"]  VDD_nRF_SENSE->Q9[label="VDD_nRF_SENSE(Gate)"]  Q9->U16[label="VSUPPLY_EN"]    V5V->VolDiv [label="V5V"][color=orange]  VolDiv -> Q8A [label="VREG_EN"]   D3->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  D5->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  D6->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  D7->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  VBOOST_SRC_DASH->SW8B[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  J3->D5  V5V->VolDiv    Q5A->Q5B[label="Gate"]  J2->VBUS->Q5A [label="VBUS"][color=gold]  U19->J4[label="VDD_IMCU"]   D3->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  D5->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  D6->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]  D7->VBOOST_SRC_DASH[label="VBOOST_SRC'"] [color=turquoise1][fontcolor=turquoise1]    U20->U1[label="VBUS_nRF"]   J4->VBUS->D3[label="VBUS"][color=gold]   J2->VBUS->D3[label="VBUS"][color=gold]   J3->U20[label="VBUS_nRF'"]     VDD->SW10A  VDD->U20[label="VDD"][color=red]   VDD->U20[label="VDD"][color=red]       J3->D5[label="VBUS_nRF'"]   D6->SW9B[label="VLi-Ion"]   J3->SW9B[label="VBUS_nRF'"]   P22->SW9B[label="VDD_nRF"]   //P27->D6[label="VLi-Ion"]   J6->D6[label="VLi-Ion"]   P20->D7[label="VIN3-5V"]   P26->D7[label="VIN3-5V"]   P25->SWD[label="SWD"] [color=blue]  P25->TRACE->U1[label="TRACE"]   VDD->U3_34[label="VDD"][color=red]   VDD->U25_34[label="VDD"][color=red]   VDD->U5[label="VDD"][color=red]   VDD->U6_12[label="VDD"][color=red]  VDD->U6_34[label="VDD"][color=red]  VDD->U4[label="VDD"][color=red]   SW6B->U4 [label="nRF_ONLY"]  U4->LED1  U4->LED2  U4->LED3  U4->LED4  J6->P27[label="VLi-Ion"]  VDD->SW6B[label="VDD"][color=red]   VDD->Q5B[label="VDD"][color=red]   VDD_nRF_SENSE->U12[label="VDD_nRF_SENSE"]   Q7->U12  U9A->Q7[label="Gate"]   VDD_nRF_SENSE->U9A[label="VDD_nRF_SENSE"]   V5V->P11[label="V5V"][color=orange]   P28->U9B  U9B->P28     // { rank=same;U3_34 U25 U25_34 U5 U6 U6_12 U6_34}            U3_12[shape="box"][fillcolor=grey, style=filled];          U3_34[shape="box"][fillcolor=grey, style=filled];                   U6_12[shape="box"][fillcolor=grey, style=filled]          U6_34[shape="box"][fillcolor=grey, style=filled]          SW10A->P21          V5V->Q6 [label="V5V"][color=orange]               //{ rank=same; U7 U1 }  subgraph clusterDIR {            color=transparent      subgraph clusterPower {          color=transparent          subgraph clusterP7_1_13 { color=transparent P7 P1 P13  }          subgraph clusterRect { P20 P26 color=transparent}           VSENSE_SW_OUT SW8A Bat1 VBOOST_SRC U10 U11 U15 Q7 Q9   P28 U12  J6 P27 P22 P23 VREG U13 U14 U16 U17 U19 VREG_EN_INV U18 U20 U21 VEXT_EN U23 VSUPPLY Q6 P21  VBOOST_SRC_DASH V5V VDD U24 SW10A VolDiv  SW8B Q8A Q8B Q10A Q10B U9A  U9B VDD_nRF_SENSE  SW9A VDD_nRF_DASH D3 D5 D6 D7          subgraph clusterP21_SW10_B { P21  SW10B }          //{ rank=same; U12 U14 }          // { rank=same; U10 U20 U15}         // { rank=same; D3 D5 D6 D7 }         // { rank=same; U18 U21 U24}        //  { rank=same; J6 P22 P23   }          //{ rank=same; U23 Q10B U13 }         // { rank=same; VolDiv U24 }           subgraph clusterJ6_P27 { J6  P27 }               }      subgraph clusterSystem {          SW5 Q5A Q5B  RESET GND           color=transparent          //subgraph clusterQ5 { Q5A Q5B  }          subgraph clusterProg { VBUS IMCU_RESET U2 X3 J2 USB2 J4 LED5 Q1 P19 U22 VBUS_IMCU SWD3 SWD0}          subgraph clusterMUX_GL {              color=transparent              SW7B SW7A  SW6A SW6B IF_OFF              subgraph clusterMUX {                  color=transparent                  U5  U3_12    U3_34 U25_12 U25_34 BOOT_RESET U6_12 U6_34                   //subgraph clusterU3 {  U3_12    U3_34 }                  //subgraph clusterU25 {  U25_12 U25_34 }                  //subgraph clusterU6 {  U6_12 U6_34 }                                  }          }          subgraph clusterMCU {              color=transparent              subgraph clusterP11_5 { P11 P5  }              subgraph clusterP12_6_17 { P12 P6 P17  }              subgraph clusterP8_2_14 { P8 P2 P14  }              subgraph clusterP9_3_15 { P9 P3 P15  }              subgraph clusterP10_4_16 { P10 P4 P16  }              J1  U4 J3 USB3 P6 P3 P4 P2 P1 P24 J5  UART_1 UART_2 I2C SWD TRACE              subgraph clusterArduino { P1 P2  P3 P4 }              subgraph clusterLED { LED1 LED2 LED3 LED4 }              subgraph clusterSW { SW1 SW2 SW3 SW4 }              subgraph clusterMem {color=transparent U1 U7               //{ rank=same; U7 U1 }              }              subgraph clusterClc {color=transparent X1 X2   }              //subgraph clusterNFC { U1 J5   }              subgraph clusterSWDMCU {color=transparent P18 P25   }              //{ rank=same; LED1 LED2 LED3 LED4 J1}          }      }  }  //{ rank=same;    VBOOST_SRC_DASH  SW8B    } }

Теперь надо сгенерировать граф в виде *.svg файла прямо по исходнику из *.dot. Вот скрипт генерации графа электрической цепи.

cls "C:\Program Files\Graphviz\bin\dot.exe" -v -Tsvg nRF5340.dot -o nRF5340_generated.svg start chrome -open %cd%/nRF5340_generated.svg 

или лучше из makefile

 CC=dot RENDER=chrome CURRENT_DIR = $(shell pwd)  SOURCES_DOT += $(CURRENT_DIR)/nRF5340.dot SOURCES_DOT := $(subst /c/,C:/, $(SOURCES_DOT)) ART_SVG := $(subst dot,svg, $(SOURCES_DOT))  OPT +=-Tsvg  all:  print_svg  clean: rm nRF5340.svg  print_svg:$(ART_SVG) $(RENDER) -open $(ART_SVG)  $(ART_SVG): $(SOURCES_DOT)   $(CC) $(OPT) $(SOURCES_DOT) -o $(ART_SVG) 

А это сгенерированный граф цепи.

Далее, глядя на граф можно перерисовать цепь аккуратнее.

Вывод

Благодаря языку разметки dot можно очень легко представлять и изучать новые аппаратные платформы, составлять блок схемы и документацию. Язык Dot можно смело использовать как hardware description language.