ADS1.2裸板調試mini2440串口 （含源碼）

~~~~~~~~~~~~~~  head.S   ~~~~~~~~~~~~~~~~~~~

 

;*******************************************
; File：head.S
; 功能：設置SDRAM，將程序複製到SDRAM，然後跳到SDRAM繼續執行
;******************************************       
                      

         IMPORT     Main         ;聲明外部引用
         IMPORT     disable_watch_dog   
         IMPORT     clock_init    
         IMPOR      memsetup  
                     
         AREA     HEAD, CODE, READONLY
         ENTRY
         CODE32  
        
start                                              ;程序入口點
Reset                  
        ldr sp, =0x32008000           ; 設置棧指針，以下都是C函數，調用前需要設好棧
        bl  disable_watch_dog         ; 關閉WATCHDOG，否則CPU會不斷重啓
        bl  clock_init                ; 設置MPLL，改變FCLK、HCLK、PCLK
        bl  memsetup                  ; 設置存儲控制器以使用SDRAM
        ldr pc, =on_sdram                   ; 跳到SDRAM中繼續執行
on_sdram
        ldr sp, =0x34000000           ; 設置棧指針，
        ldr lr, =halt_loop            ; 設置返回地址
        ldr pc, =Main                 ; 調用main函數
halt_loop
        b   halt_loop

         END

 

 

################  init.c   #################

/*
 * init.c: 進行一些初始化
 */

#include "s3c24xx.h"
 
void disable_watch_dog(void);
void clock_init(void);
void memsetup(void);

/*
 * 關閉WATCHDOG，否則CPU會不斷重啓
 */

void disable_watch_dog(void)
{
    WTCON = 0;  // 關閉WATCHDOG很簡單，往這個寄存器寫0即可
}

 

#define S3C2440_MPLL_200MHZ     ((0x5c<<12)|(0x01<<4)|(0x02))
/*
 * 對於MPLLCON寄存器，[19:12]爲MDIV，[9:4]爲PDIV，[1:0]爲SDIV
 * 有如下計算公式：
 *  S3C2440: MPLL(FCLK) = (2 * m * Fin)/(p * 2^s)
 *  其中: m = MDIV + 8, p = PDIV + 2, s = SDIV
 * 對於本開發板，Fin = 12MHz
 * 設置CLKDIVN，令分頻比爲：FCLK:HCLK:PCLK=1:2:4，
 * FCLK=200MHz,HCLK=100MHz,PCLK=50MHz
 */

void clock_init(void)
{
    CLKDIVN  = 0x03;            // FCLK:HCLK:PCLK=1:2:4, HDIVN=1,PDIVN=1

    /* 如果HDIVN非0，CPU的總線模式應該從“fast bus mode”變爲“asynchronous bus mode” */
__asm{
    mrc    p15, 0, r1, c1, c0, 0        /* 讀出控制寄存器 */ 
    orr    r1, r1, #0xc0000000          /* 設置爲“asynchronous bus mode” */
    mcr    p15, 0, r1, c1, c0, 0        /* 寫入控制寄存器 */
    }

    MPLLCON = S3C2440_MPLL_200MHZ;  /* 現在，FCLK=200MHz,HCLK=100MHz,PCLK=50MHz */
}

 

/*
 * 設置存儲控制器以使用SDRAM
 */

void memsetup(void)
{
    volatile unsigned long *p = (volatile unsigned long *)MEM_CTL_BASE;

    /* 這個函數之所以這樣賦值，而不是像前面的實驗(比如mmu實驗)那樣將配置值
     * 寫在數組中，是因爲要生成”位置無關的代碼”，使得這個函數可以在被複制到
     * SDRAM之前就可以在steppingstone中運行
     */
    /* 存儲控制器13個寄存器的值 */
    p[0] = 0x22011110;     //BWSCON
    p[1] = 0x00000700;     //BANKCON0
    p[2] = 0x00000700;     //BANKCON1
    p[3] = 0x00000700;     //BANKCON2
    p[4] = 0x00000700;     //BANKCON3  
    p[5] = 0x00000700;     //BANKCON4
    p[6] = 0x00000700;     //BANKCON5
    p[7] = 0x00018005;     //BANKCON6
    p[8] = 0x00018005;     //BANKCON7
    
                                            /* REFRESH,
                                             * HCLK=12MHz:  0x008C07A3,
                                             * HCLK=100MHz: 0x008C04F4
                                             */ 
    p[9]  = 0x008C04F4;
    p[10] = 0x000000B1;     //BANKSIZE
    p[11] = 0x00000030;     //MRSRB6
    p[12] = 0x00000030;     //MRSRB7
}

$$$$$$$$$$$$$$$$  serial.h   $$$$$$$$$$$$$$$

 

void uart0_init(void);
void putc(unsigned char c);
unsigned char getc(void);
int isDigit(unsigned char c);
int isLetter(unsigned char c);

 

****************  serial.c  ****************

#include "s3c24xx.h"
#include "serial.h"

#define TXD0READY   (1<<2)
#define RXD0READY   (1)

#define PCLK            50000000    // init.c中的clock_init函數設置PCLK爲50MHz
#define UART_CLK        PCLK        //  UART0的時鐘源設爲PCLK
#define UART_BAUD_RATE  115200      // 波特率
#define UART_BRD        ((UART_CLK  / (UART_BAUD_RATE * 16)) - 1)

/*
 * 初始化UART0
 * 115200,8N1,無流控
 */
void uart0_init(void)
{
    GPHCON  |= 0xa0;    // GPH2,GPH3用作TXD0,RXD0
    GPHUP   = 0x0c;     // GPH2,GPH3內部上拉

    ULCON0  = 0x03;     // 8N1(8個數據位，無較驗，1個停止位)
    UCON0   = 0x05;     // 查詢方式，UART時鐘源爲PCLK
    UFCON0  = 0x00;     // 不使用FIFO
    UMCON0  = 0x00;     // 不使用流控
    UBRDIV0 = UART_BRD; // 波特率爲115200
   

}

/*
 * 發送一個字符
 */
void putc(unsigned char c)
{
    /* 等待，直到發送緩衝區中的數據已經全部發送出去 */
    while (!(UTRSTAT0 & TXD0READY));
    
    /* 向UTXH0寄存器中寫入數據，UART即自動將它發送出去 */
    UTXH0 = c;
}

/*
 * 接收字符
 */
unsigned char getc(void)
{
    /* 等待，直到接收緩衝區中的有數據 */
    while (!(UTRSTAT0 & RXD0READY));
    
    /* 直接讀取URXH0寄存器，即可獲得接收到的數據 */
    return URXH0;
}

/*
 * 判斷一個字符是否數字
 */
int isDigit(unsigned char c)
{
    if (c >= '0' && c <= '9')
        return 1;
    else
        return 0;       
}

/*
 * 判斷一個字符是否英文字母
 */
int isLetter(unsigned char c)
{
    if (c >= 'a' && c <= 'z')
        return 1;
    else if (c >= 'A' && c <= 'Z')
        return 1;       
    else
        return 0;
}

 

&&&&&&&&&&&&&  main.c &&&&&&&&&&&&&&&&&&

 

#include "serial.h"
int Main()
{
    unsigned char c;
    uart0_init();   // 波特率115200，8N1(8個數據位，無校驗位，1個停止位)

    while(1)
    {
         // 從串口接收數據後，判斷其是否數字或子母，若是則加2後輸出
        c = getc();                       //接收數據
        if (isDigit(c) || isLetter(c))     //判斷
            putc(c+2);                      //加2後輸出
   }

    return 0;
}

 

 

%%%%%%%%%%%%%  s3c2440   %%%%%%%%%%%%%%%%%%%

/* WOTCH DOG register */
#define     WTCON           (*(volatile unsigned long *)0x53000000)

/* SDRAM regisers */
#define     MEM_CTL_BASE    0x48000000
#define     SDRAM_BASE      0x30000000

/* NAND Flash registers */
#define NFCONF              (*(volatile unsigned int  *)0x4e000000)
#define NFCMD               (*(volatile unsigned char *)0x4e000004)
#define NFADDR              (*(volatile unsigned char *)0x4e000008)
#define NFDATA              (*(volatile unsigned char *)0x4e00000c)
#define NFSTAT              (*(volatile unsigned char *)0x4e000010)

/*GPIO registers*/
#define GPBCON              (*(volatile unsigned long *)0x56000010)
#define GPBDAT              (*(volatile unsigned long *)0x56000014)

#define GPFCON              (*(volatile unsigned long *)0x56000050)
#define GPFDAT              (*(volatile unsigned long *)0x56000054)
#define GPFUP               (*(volatile unsigned long *)0x56000058)

#define GPGCON              (*(volatile unsigned long *)0x56000060)
#define GPGDAT              (*(volatile unsigned long *)0x56000064)
#define GPGUP               (*(volatile unsigned long *)0x56000068)

#define GPHCON              (*(volatile unsigned long *)0x56000070)
#define GPHDAT              (*(volatile unsigned long *)0x56000074)
#define GPHUP               (*(volatile unsigned long *)0x56000078)

 

/*UART registers*/
#define ULCON0              (*(volatile unsigned long *)0x50000000)
#define UCON0               (*(volatile unsigned long *)0x50000004)
#define UFCON0              (*(volatile unsigned long *)0x50000008)
#define UMCON0              (*(volatile unsigned long *)0x5000000c)
#define UTRSTAT0            (*(volatile unsigned long *)0x50000010)
#define UTXH0               (*(volatile unsigned char *)0x50000020)
#define URXH0               (*(volatile unsigned char *)0x50000024)
#define UBRDIV0             (*(volatile unsigned long *)0x50000028)

/*interrupt registes*/
#define SRCPND              (*(volatile unsigned long *)0x4A000000)
#define INTMOD              (*(volatile unsigned long *)0x4A000004)
#define INTMSK              (*(volatile unsigned long *)0x4A000008)
#define PRIORITY            (*(volatile unsigned long *)0x4A00000c)
#define INTPND              (*(volatile unsigned long *)0x4A000010)
#define INTOFFSET           (*(volatile unsigned long *)0x4A000014)
#define SUBSRCPND           (*(volatile unsigned long *)0x4A000018)
#define INTSUBMSK           (*(volatile unsigned long *)0x4A00001c)

/*external interrupt registers*/
#define EINTMASK            (*(volatile unsigned long *)0x560000a4)
#define EINTPEND            (*(volatile unsigned long *)0x560000a8)

/*clock registers*/
#define LOCKTIME  (*(volatile unsigned long *)0x4c000000)
#define MPLLCON  (*(volatile unsigned long *)0x4c000004)
#define UPLLCON  (*(volatile unsigned long *)0x4c000008)
#define CLKCON  (*(volatile unsigned long *)0x4c00000c)
#define CLKSLOW  (*(volatile unsigned long *)0x4c000010)
#define CLKDIVN  (*(volatile unsigned long *)0x4c000014)

/*PWM & Timer registers*/
#define TCFG0  (*(volatile unsigned long *)0x51000000)
#define TCFG1  (*(volatile unsigned long *)0x51000004)
#define TCON  (*(volatile unsigned long *)0x51000008)
#define TCNTB0  (*(volatile unsigned long *)0x5100000c)
#define TCMPB0  (*(volatile unsigned long *)0x51000010)
#define TCNTO0  (*(volatile unsigned long *)0x51000014)

#define GSTATUS1    (*(volatile unsigned long *)0x560000B0)