使用keil SDK方式点亮mini2440的led灯
最近在使用mini2440做开发，网上很多教程和实际操作不太一致，导致入门花费时间长。经过整理，目前mini2440点亮led灯方法有，keil mdk，linux环境编译，使用minitools下载即可。
mini2440分为nor flash和nand flash两种，一般小于4k程序可以直接运行，大于4K的程序需要预先加载引导程序，从存储位置拷贝至内存中。下面来说说mini2440究竟是如何点亮led灯的。
方法一：使用keil mdk的方式，首先下载MDK，使keil包含s3c2440这款芯片。根据该芯片创建工程，添加S3C2440.S文件。工程创建完成后，编写led.c文件代码如下
#define rGPBCON (*(volatile unsigned long *)0x56000010) #define rGPBDAT (*(volatile unsigned long *)0x56000014) #define rGPBUP (*(volatile unsigned long *)0x56000018) #define GPB5_IN ~(3<<10) #define GPB6_IN ~(3<<12) #define GPB7_IN ~(3<<14) #define GPB8_IN ~(3<<16) #define GPB5_OUT (1<<10) #define GPB6_OUT (1<<12) #define GPB7_OUT (1<<14) #define GPB8_OUT (1<<16) #define LED1_ON ~(1<<5) #define LED2_ON ~(1<<6) #define LED3_ON ~(1<<7) #define LED4_ON ~(1<<8) #define LED1_OFF (1<<5) #define LED2_OFF (1<<6) #define LED3_OFF (1<<7) #define LED4_OFF (1<<8) void Led_Port_Init(void); void Delay(int tt); void main() { Led_Port_Init(); rGPBDAT |= (LED1_OFF|LED2_OFF|LED3_OFF|LED4_OFF); rGPBDAT |= (LED1_OFF|LED2_OFF|LED3_OFF|LED4_OFF); while(1) { rGPBDAT = rGPBDAT&(LED1_ON); Delay(10); rGPBDAT = rGPBDAT|((LED1_OFF)|(LED2_OFF)|(LED3_OFF)|(LED4_OFF)); Delay(10); rGPBDAT = rGPBDAT&(LED2_ON); Delay(10); rGPBDAT = rGPBDAT|((LED1_OFF)|(LED2_OFF)|(LED3_OFF)|(LED4_OFF)); Delay(10); rGPBDAT = rGPBDAT&(LED3_ON); Delay(10); rGPBDAT = rGPBDAT|((LED1_OFF)|(LED2_OFF)|(LED3_OFF)|(LED4_OFF)); Delay(10); rGPBDAT = rGPBDAT&(LED4_ON); Delay(10); rGPBDAT = rGPBDAT|((LED1_OFF)|(LED2_OFF)|(LED3_OFF)|(LED4_OFF)); Delay(10); } } void Led_Port_Init(void) { rGPBCON &= ~((3<<10)|(3<<12)|(3<<14)|(3<<16)); rGPBCON |= (1<<10)|(1<<12)|(1<<14)|(1<<16); } void Delay(int tt) { int a,b; for(a=0;a<=tt;a++) for(b=0;b<=10000;b++); }
完成编辑后进入到关键环节，就是配置界面要选择好。（需说明的是Keil MDK 支持Nor Flash下载和仿真状态，nand flash目前没找到下载方法）
图1 程序配置
目标界面设置如改图1所示，从配置界面可以看出，程序将拷贝至ROM空间，空间大小为2M。芯片上电运行将程序拷贝至RAM地址空间0x30000000处大小为2M开始运行。
图2 烧写驱动选择J-LINK / J-TRACE ARM
图3 配置Jlink的flash烧写函数
如图2、3所示，配置目标芯片的烧写函数，选择应用的nor flash芯片。Use Target Driver勾选，取消Use debug driver和Upadate Target选项勾选。
图3 使目标编译程序产生bin文件
图4 勾选产生HEX File
其他界面如图3、图4所示。
图5 设置Ext_RAM.ini
设置完成后，编译程序，点击Load下载目标程序。下载目标前注意图5Ext_RAM.ini中的设置。函数设置如下：
/******************************************************************************/ /* Ext_RAM.INI: External RAM (SDRAM) Initialization File */ /******************************************************************************/ // <<< Use Configuration Wizard in Context Menu >>> // /******************************************************************************/ /* This file is part of the uVision/ARM development tools. */ /* Copyright (c) 2005-2008 Keil Software. All rights reserved. */ /* This software may only be used under the terms of a valid, current, */ /* end user licence from KEIL for a compatible version of KEIL software */ /* development tools. Nothing else gives you the right to use this software. */ /******************************************************************************/ 0x200000 FUNC void Init (void) { _WDWORD(0x4A000008, 0xFFFFFFFF); // Disable All Interrupts _WDWORD(0x53000000, 0x00000000); // Disable Watchdog Timer // Clock Setup // FCLK = 300 MHz, HCLK = 100 MHz, PCLK = 50 MHz _WDWORD(0x4C000000, 0x0FFF0FFF); // LOCKTIME _WDWORD(0x4C000014, 0x0000000F); // CLKDIVN _WDWORD(0x4C000004, 0x00043011); // MPLLCON _WDWORD(0x4C000008, 0x00038021); // UPLLCON _WDWORD(0x4C00000C, 0x001FFFF0); // CLKCON // Memory Controller Setup for SDRAM _WDWORD(0x48000000, 0x22000000); // BWSCON _WDWORD(0x4800001C, 0x00018005); // BANKCON6 _WDWORD(0x48000020, 0x00018005); // BANKCON7 _WDWORD(0x48000024, 0x008404F3); // REFRESH _WDWORD(0x48000028, 0x00000032); // BANKSIZE _WDWORD(0x4800002C, 0x00000020); // MRSRB6 _WDWORD(0x48000030, 0x00000020); // MRSRB7 _WDWORD(0x56000000, 0x000003FF); // GPACON: Enable Address lines for SDRAM } // Reset chip with watchdog, because nRST line is routed on hardware in a way // that it can not be pulled low with ULINK _WDWORD(0x40000000, 0xEAFFFFFE); // Load RAM addr 0 with branch to itself CPSR = 0x000000D3; // Disable interrupts //CPSR = 0x00000063; // Disable interrupts PC = 0x40000000; // Position PC to start of RAM _WDWORD(0x53000000, 0x00000021); // Enable Watchdog g, 0 // Wait for Watchdog to reset chip Init(); // Initialize memory LOAD obj\led.axf INCREMENTAL // Download program PC = 0x30000000; // Setup for Running g, main // Goto Main
注意修改该行代码与当前工程生成文件名一致，LOAD obj\led.axf INCREMENTAL // Download program
