PIC18 Configuration Bits教學(基礎設定)

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在開始Configuration Bits教學前，要先確認你的硬體接線是否有正確，請參考我之前的這篇PIC18F25K83硬體介紹的文章，對於PIC18F25K83的微處理機來說，Configuration Bits會設定一些基礎的核心設定(例如時脈等)，大部分的時候你的設定都會是類似的，但有時也會因為有特殊需求，會需要修改這裡的設定。

另外會因為每個人使用的PIC晶片不同，Configuration Bits顯示的文字就會改變，可以參考那顆晶片的Datasheet，我使用PIC18F25K83作為範例，但大致的設定邏輯都是一樣的，時脈、看門狗這些，都要記得設定。

PIC18F25K83的Datasheet順便給你參考：

首先開啟你的Configuration Bits

參考PIC18F25K83的Datasheet中的第7章和第11章，得知Configuration Bits有兩個要改分別是：

• FEXTOSC（External Oscillator Selection；外接石英震盪器）：選擇HS，因為我接16MHz的石英震盪器做為微處理機的系統時脈。
  

• WDTE（WDT operating mode；看門狗…不是遊戲的那個…） ：選擇OFF，若選擇ON的話，若在設定的時間內不將其計時器歸零的話，會當成微處理機當機，自動重置系統，會變成一直在重新重置系統，沒有動作反應。這篇文章有更詳細的說明。

CP的設定千萬不要動到，一定要設為OFF！！！
CP的設定千萬不要動到，一定要設為OFF！！！
CP的設定千萬不要動到，一定要設為OFF！！！
若將它設為ON，會導致程式無法重複進行燒錄，會將整顆晶片燒死，除非你是要做最終的產品，否則這個在開發階段都要設為OFF。

按下Generate Source Code to Output，產生基礎的設定碼。

在剛剛新增的專案中，創建一個標頭(Configuration.h)檔案，用來放剛剛Configuration Bits產生出來的程式碼。

全選並複製產生出來的程式碼

刪除掉「include <xc.h>」到「ifdef __cplusplus」中間的灰色註解(藍色X的部分)，並貼上剛剛複製的程式碼，記得存檔！

完整的Configuration.h的程式碼長得如下：

/* Microchip Technology Inc. and its subsidiaries.  You may use this software 
 * and any derivatives exclusively with Microchip products. 
 * 
 * THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS".  NO WARRANTIES, WHETHER 
 * EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, INCLUDING ANY IMPLIED 
 * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A 
 * PARTICULAR PURPOSE, OR ITS INTERACTION WITH MICROCHIP PRODUCTS, COMBINATION 
 * WITH ANY OTHER PRODUCTS, OR USE IN ANY APPLICATION. 
 *
 * IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, 
 * INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND 
 * WHATSOEVER RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS 
 * BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE.  TO THE 
 * FULLEST EXTENT ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS 
 * IN ANY WAY RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT OF FEES, IF 
 * ANY, THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
 *
 * MICROCHIP PROVIDES THIS SOFTWARE CONDITIONALLY UPON YOUR ACCEPTANCE OF THESE 
 * TERMS. 
 */

/* 
 * File:   
 * Author: 
 * Comments:
 * Revision history: 
 */

// This is a guard condition so that contents of this file are not included
// more than once.  
#ifndef XC_HEADER_TEMPLATE_H
#define	XC_HEADER_TEMPLATE_H

#include  // include processor files - each processor file is guarded.  


// PIC18F25K83 Configuration Bit Settings

// 'C' source line config statements

// CONFIG1L
#pragma config FEXTOSC = HS     // External Oscillator Selection (HS (crystal oscillator) above 8 MHz; PFM set to high power)
#pragma config RSTOSC = EXTOSC  // Reset Oscillator Selection (EXTOSC operating per FEXTOSC bits (device manufacturing default))

// CONFIG1H
#pragma config CLKOUTEN = OFF   // Clock out Enable bit (CLKOUT function is disabled)
#pragma config PR1WAY = ON      // PRLOCKED One-Way Set Enable bit (PRLOCK bit can be cleared and set only once)
#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)
#pragma config FCMEN = ON       // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor enabled)

// CONFIG2L
#pragma config MCLRE = EXTMCLR  // MCLR Enable bit (If LVP = 0, MCLR pin is MCLR; If LVP = 1, RE3 pin function is MCLR )
#pragma config PWRTS = PWRT_OFF // Power-up timer selection bits (PWRT is disabled)
#pragma config MVECEN = ON      // Multi-vector enable bit (Multi-vector enabled, Vector table used for interrupts)
#pragma config IVT1WAY = ON     // IVTLOCK bit One-way set enable bit (IVTLOCK bit can be cleared and set only once)
#pragma config LPBOREN = OFF    // Low Power BOR Enable bit (ULPBOR disabled)
#pragma config BOREN = SBORDIS  // Brown-out Reset Enable bits (Brown-out Reset enabled , SBOREN bit is ignored)

// CONFIG2H
#pragma config BORV = VBOR_2P45 // Brown-out Reset Voltage Selection bits (Brown-out Reset Voltage (VBOR) set to 2.45V)
#pragma config ZCD = OFF        // ZCD Disable bit (ZCD disabled. ZCD can be enabled by setting the ZCDSEN bit of ZCDCON)
#pragma config PPS1WAY = ON     // PPSLOCK bit One-Way Set Enable bit (PPSLOCK bit can be cleared and set only once; PPS registers remain locked after one clear/set cycle)
#pragma config STVREN = ON      // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset)
#pragma config DEBUG = OFF      // Debugger Enable bit (Background debugger disabled)
#pragma config XINST = OFF      // Extended Instruction Set Enable bit (Extended Instruction Set and Indexed Addressing Mode disabled)

// CONFIG3L
#pragma config WDTCPS = WDTCPS_31// WDT Period selection bits (Divider ratio 1:65536; software control of WDTPS)
#pragma config WDTE = OFF       // WDT operating mode (WDT Disabled; SWDTEN is ignored)

// CONFIG3H
#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)
#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

// CONFIG4L
#pragma config BBSIZE = BBSIZE_512// Boot Block Size selection bits (Boot Block size is 512 words)
#pragma config BBEN = OFF       // Boot Block enable bit (Boot block disabled)
#pragma config SAFEN = OFF      // Storage Area Flash enable bit (SAF disabled)
#pragma config WRTAPP = OFF     // Application Block write protection bit (Application Block not write protected)

// CONFIG4H
#pragma config WRTB = OFF       // Configuration Register Write Protection bit (Configuration registers (300000-30000Bh) not write-protected)
#pragma config WRTC = OFF       // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)
#pragma config WRTD = OFF       // Data EEPROM Write Protection bit (Data EEPROM not write-protected)
#pragma config WRTSAF = OFF     // SAF Write protection bit (SAF not Write Protected)
#pragma config LVP = ON         // Low Voltage Programming Enable bit (Low voltage programming enabled. MCLR/VPP pin function is MCLR. MCLRE configuration bit is ignored)

// CONFIG5L
#pragma config CP = OFF         // PFM and Data EEPROM Code Protection bit (PFM and Data EEPROM code protection disabled)

// CONFIG5H

// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.

#include 




#ifdef	__cplusplus
extern "C" {
#endif /* __cplusplus */

    // TODO If C++ is being used, regular C code needs function names to have C 
    // linkage so the functions can be used by the c code. 

#ifdef	__cplusplus
}
#endif /* __cplusplus */

#endif	/* XC_HEADER_TEMPLATE_H */

---

當設定好核心的程式檔(Configuration.h)，就來新增主程式(main.c)的檔案啦~

新增main.c檔案後，長的會像是這樣：

並在前面新增下面這一行程式碼，匯入剛剛我們設定的Configuration Bits的程式碼。

#include "Configuration.h"

按下那根榔頭(Build Main Project F11)，編譯程式，若程式下面顯示BUILD SUCCESSFUL，及代表程式編譯完成，接下來就可以開始寫你想要的功能啦！

下面是main.c檔案的完整程式碼：

/*
 * File:   main.c
 * Author: roy
 *
 * Created on June 18, 2021, 10:05 PM
 */


#include 
#include "Configuration.h"

void main(void) {
    return;
}

基本上的操作步驟是不管你寫甚麼功能時，都會需要做的建立與檢察，若有任何問題，歡迎在下面與我討論！