CCS5.4+Proteus8的F28027实践课十一、串行12864

xiaoxiao2025-06-19 7

周末出去玩了两天，刚到家，昨天有个同学咨询串行12864的东西，真不好意思，现在才以博客的形式来解答。所谓12864的串行控制，只用到了三根线：CS、SID、SCLK，其中CS信号用来选择控制数据和指令的输入，SID就是数据线，SCLK使能信号线。了解了几个引脚，我们再来看下时序图：从时序图可以看出来，每一次操作都要写入三个字节：控制字节、高四位、低四位。其中写指令的时候是0xf8+cmd&0xf0+(cmd<<4)&0xf0，写数据是0xfa+data&0xf0+(data<<4)&0xf0。另外还有一点就是，数据是下降沿写入，昨天那位同学应该是这里出错了。好了，需要了解的理论知识就这么多，我们现在开始写程序。先写F2802x_LCD12864.h文件

再写F2802x_LCD12864.c文件

// auther: wangdingfa // Checkin $Date: July 31, 2016 22:45:31 $ //########################################################################### // // FILE: F2802x_LCD12864.c // // TITLE: LCD12864 Initialization & Support Functions. // #include "F2802x_Device.h" // Headerfile Include File #include "F2802x_Examples.h" // Examples Include File void SendByte_LCD12864(unsigned char byte) { char i; CS=1; for(i = 0;i < 8;i ++) { if((byte<<i) & 0x80) { SID = 1; } else { SID = 0; } DELAY_US(1); SCLK = 1; DELAY_US(1); SCLK = 0; DELAY_US(1); } DELAY_US(10); } //--------------------------------------------------------------------------- // WRITEDATA_LCD12864: //--------------------------------------------------------------------------- // This function writes data to LCD12864 void WRITEDATA_LCD12864(unsigned char data) { CS = 1; //打开片选 DELAY_US(10); SendByte_LCD12864(0xfa);//第一字节 DELAY_US(10); SendByte_LCD12864(data & 0xf0); //第二字节 DELAY_US(10); SendByte_LCD12864((data << 4) & 0xf0);//第三字节 DELAY_US(10); CS = 0; DELAY_US(100); } //--------------------------------------------------------------------------- // WRITECMD_LCD12864: //--------------------------------------------------------------------------- // This function writes cmd to LCD12864 void WRITECMD_LCD12864(unsigned char cmd) { CS = 1;//打开片选，高电平有效 DELAY_US(10); SendByte_LCD12864(0xf8); //第一字节 DELAY_US(10); SendByte_LCD12864(cmd & 0xf0); //第二字节 DELAY_US(10); SendByte_LCD12864((cmd << 4) & 0xf0);//第三字节 DELAY_US(10); CS = 0; DELAY_US(100); } //--------------------------------------------------------------------------- // InitLCD12864: //--------------------------------------------------------------------------- // This function initializes the LCD12864 to a known (default) state. // such as FUNCTION SET,DSIPLAY SET,CLEAR SCREEN void InitLCD12864(void) { DELAY_US(10000); WRITECMD_LCD12864(0x30); DELAY_US(1000); WRITECMD_LCD12864(0x30); DELAY_US(100); WRITECMD_LCD12864(0x0c); DELAY_US(1000); WRITECMD_LCD12864(0x01); DELAY_US(10000); WRITECMD_LCD12864(0x06); DELAY_US(10000); } //=========================================================================== // End of file. //===========================================================================

最后还是主函数，这个主函数跟上次并行的一样，都是测试语句而已

#include "DSP28x_Project.h" // Device Headerfile and Examples Include File void main(void) { // Step 1. Initialize System Control: // PLL, WatchDog, enable Peripheral Clocks // This example function is found in the DSP2802x_SysCtrl.c file. InitSysCtrl(); // Step 2. Initalize GPIO: // This example function is found in the DSP2802x_Gpio.c file and // illustrates how to set the GPIO to it's default state. InitGpio(); // Step 3. Clear all interrupts and initialize PIE vector table: // Disable CPU interrupts DINT; // Initialize PIE control registers to their default state. // The default state is all PIE interrupts disabled and flags // are cleared. // This function is found in the DSP2802x_PieCtrl.c file. InitPieCtrl(); // Disable CPU interrupts and clear all CPU interrupt flags: IER = 0x0000; IFR = 0x0000; // Initialize the PIE vector table with pointers to the shell Interrupt // Service Routines (ISR). // This will populate the entire table, even if the interrupt // is not used in this example. This is useful for debug purposes. // The shell ISR routines are found in DSP2802x_DefaultIsr.c. // This function is found in DSP2802x_PieVect.c. InitPieVectTable(); // Step 4. Initialize all the Device Peripherals: // This function is found in DSP2802x_InitPeripherals.c // InitPeripherals(); // Not required for this example // Step 5. User specific code: InitLCD12864(); WRITECMD_LCD12864(0x80); WRITEDATA_LCD12864('a'); WRITEDATA_LCD12864('b'); WRITEDATA_LCD12864('c'); WRITECMD_LCD12864(0x90); WRITEDATA_LCD12864('1'); WRITEDATA_LCD12864('2'); WRITEDATA_LCD12864('3'); WRITECMD_LCD12864(0x88); WRITEDATA_LCD12864('x'); WRITEDATA_LCD12864('y'); WRITEDATA_LCD12864('z'); WRITECMD_LCD12864(0x98); WRITEDATA_LCD12864('7'); WRITEDATA_LCD12864('8'); WRITEDATA_LCD12864('9'); while(1) { // GpioDataRegs.GPATOGGLE.all=0x000000ff; // DELAY_US(1000); } }

下载测试，结果正确，那说明昨天那位同学出错的地方就是数据写入跳变沿选择错了，应该是下降沿有效，而不是上升沿。洗洗睡了，昨晚喝酒喝太多了，现在头还有点晕晕的，老了，恢复的比较慢。 F28027菜鸟交流qq群107691092

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