S3C2440裸機程式【2】串列埠uart程式
阿新 • • 發佈：2018-12-08
學習ARM7晶片stm32時，裸機程式開發可以很方便的根據庫函式在工程模板上進行開發，而ARM9主要是移植Linux開發，很少有裸機程式開發，因此在玩S3C2440希望最終形成一個keil環境下的模板。用的淘寶上的JZ2440v2板子，因為是裸機程式開發其他板子都一樣。
S3C2440.s是keil自動生成的啟動檔案，其他都是按stm32庫函式模板寫的，技術很差，自學娛樂，若有需求可自行改動。
main.c檔案：
#include "S3C2440Reg.h" #include "S3C2440Init.h" #include "led.h" #include "uart.h" void delay(int t) { int a,b; for(a=0;a<t;a++) for(b=0;b<100;b++); } int main(void) { unsigned char ch; Led_Port_Init(); uart0_init(); while(1) { GPFDAT &= Led2_On; delay(1000); GPFDAT |= Led2_Off; delay(1000); uart0SendString(" \r\nInput a char: "); ch = uart0ReceiveData(); uart0SendData(ch); } return 0; }
暫存器對映表S3C2440Reg.h檔案
#ifndef __S3C2440REG_H #define __S3C2440REG_H typedef unsigned char uint8; typedef signed char int8; typedef unsigned short uint16; typedef signed short int16; typedef unsigned int uint32; typedef signed int int32; typedef float fp32; typedef double fp64; /* 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) #endif
初始化檔案S3C2440Init.h
#ifndef __S3C2440Init_H #define __S3C2440Init_H /* Main clock */ #define FIN (12000000) #define FCLK 400000000 #define HCLK (FCLK/4) #define PCLK (HCLK/2) /* USB clock */ #define UCLK 48000000 /* BUSWIDTH : 16,32 */ #define BUSWIDTH (32) /*64MB * 0x30000000 ~ 0x30ffffff : Download Area (16MB) Cacheable * 0x31000000 ~ 0x33feffff : Non-Cacheable Area * 0x33ff0000 ~ 0x33ff47ff : Heap & RW Area * 0x33ff4800 ~ 0x33ff7fff : FIQ ~ User Stack Area * 0x33ff8000 ~ 0x33fffeff : Not Useed Area * 0x33ffff00 ~ 0x33ffffff : Exception & ISR Vector Table */ #define _RAM_STARTADDRESS 0x30000000 #define _ISR_STARTADDRESS 0x33ffff00 #define _MMUTT_STARTADDRESS 0x33ff8000 #define _STACK_BASEADDRESS 0x33ff8000 #define _NONCACHE_STARTADDRESS 0x31000000 /*USB Device Options */ #define USBDMA 1 #define USBDMA_DEMAND 0 /* the downloadFileSize should be (64*n) */ #define BULK_PKT_SIZE 64 #define UPDATE_REFRESH(IN_HCLK) ( rREFRESH = (rREFRESH & ~(0x7ff)) | 2049-(U32)((float)IN_HCLK*7.8/1000000) ) /* CLKSEL0/1 Clock selection value define */ #define CLK_HCLK (3) #define CLK_PCLK (4) #define CLK_DCLK (5) #define MEGA (1000000) #include "S3C2440Reg.h" void disable_watch_dog(void); #endif
串列埠設定檔案uart.c
#include "uart.h"
#define UART_CLK PCLK // UART0ʱÖÓÉèÖÃ
#define UART_BAUD_RATE 115200 // ²¨ÌØÂÊÉèÖÃ
#define UART_BRD ((UART_CLK / (UART_BAUD_RATE * 16)) - 1)
//#define TXD0READY (1<<2)
//#define RXD0READY (1)
/*
* ³õʼ»¯UART0
* 115200,8N1,ÎÞÁ÷¿Ø
*/
void uart0_init(void)
{
GPHCON |= 0xa0; // GPH2,GPH3ÓÃ×÷TXD0,RXD0
GPHUP = 0x0c; // GPH2,GPH3ÄÚ²¿ÉÏÀ
ULCON0 = 0x03; // 8N1
UCON0 = 0x05; // ²éѯ·½Ê½,UARTʱÖÓΪPCLK
UFCON0 = 0x00; // ²»Ê¹ÓÃFIFO
UMCON0 = 0x00; // ²»Ê¹ÓÃÁ÷¿Ø
UBRDIV0 = UART_BRD; // ²¨ÌØÂÊ115200
}
/*
* ·¢ËÍÒ»¸ö×Ö·û
*/
void uart0SendData(unsigned char ch)
{
//Ö±µ½·¢ËÍ»º³åÇøÊý¾ÝÒÑÈ«²¿·¢³ö
while (!(UTRSTAT0 & 0x4));
UTXH0 = ch;
}
/*
* ·¢ËÍÒ»¸ö×Ö·û´®
*/
void uart0SendString(unsigned char *str)
{
while(0!=*str)
{
uart0SendData(*str);
str++;
}
}
/*
* ½ÓÊÕÒ»¸ö×Ö·û
*/
unsigned char uart0ReceiveData(void)
{
//Ö±µ½½ÓÊÕ»º³åÇøÓÐÊý¾Ý
while (!(UTRSTAT0 & 0x1));
return URXH0;
}
註釋為亂碼，應該是編譯器設定問題。
硬體上：nCTS0--->GPH0，nRTS0--->GPH1，TXD0--->GPH2，RXD0--->GPH3
查詢S3C2440使用者手冊，相關串列埠控制暫存器設定如下：
因此，ULCON0 = 0x03; //8位傳輸，無校驗，一位停止位
因此，UCON0 = 0x05; //選擇PCLK作為串列埠時鐘，傳送和接收都是中斷或者查詢模式(polling mode)
因此，UFCON0 = 0x00;//不使用FIFO，每個UART通道包含了兩個64-byte的FIFO佇列用於接收器和傳送器，可以儲存更多數。
因此，UMCON0 = 0x00;//不使用流控，只需要接Rxd0和Txd0，不用接nCTS0和nRTS0
狀態暫存器
最終程式碼連線：http://download.csdn.net/detail/tiandawangliang/9549257