小会 · 2022年12月18日 · 河南

【GD32F427开发板试用】EXMC方式驱动LCD屏幕

使用EXMC方式驱动LCD显示屏。

GD32F427VEXMC系统架构图
20221218222024.png

扩展板硬件

扩展板硬件EXMC接口部分电路图

2.1、开发板接口部分
20221218224239.png

2.2、LCD接口部分
20221218224348.png

驱动程序

3.1、exmc.c

#include "gd32f4xx.h"
#include "exmc_lcd.h"

/*!
    \brief      lcd peripheral initialize
    \param[in]  none 
    \param[out] none
    \retval     none
*/
void exmc_lcd_init(void)
{
    exmc_norsram_parameter_struct lcd_init_struct;
    exmc_norsram_timing_parameter_struct lcd_timing_init_struct;

    /* EXMC clock enable */
    rcu_periph_clock_enable(RCU_EXMC);

    /* GPIO clock enable */
    rcu_periph_clock_enable(RCU_GPIOD);
    rcu_periph_clock_enable(RCU_GPIOE);
    
        /* configure GPIO D[0-15] */
    gpio_af_set(GPIOD, GPIO_AF_12, GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_8 | GPIO_PIN_9 |
                GPIO_PIN_10 | GPIO_PIN_14 | GPIO_PIN_15);
    gpio_mode_set(GPIOD, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_8 | GPIO_PIN_9 |
                  GPIO_PIN_10 | GPIO_PIN_14 | GPIO_PIN_15);
    gpio_output_options_set(GPIOD, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_8 | GPIO_PIN_9 |
                            GPIO_PIN_10 | GPIO_PIN_14 | GPIO_PIN_15);

    gpio_af_set(GPIOE, GPIO_AF_12, GPIO_PIN_7 | GPIO_PIN_8 | GPIO_PIN_9 | GPIO_PIN_10 |
                GPIO_PIN_11 | GPIO_PIN_12 | GPIO_PIN_13 | GPIO_PIN_14 | GPIO_PIN_15);
    gpio_mode_set(GPIOE, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_7 | GPIO_PIN_8 | GPIO_PIN_9 | GPIO_PIN_10 |
                  GPIO_PIN_11 | GPIO_PIN_12 | GPIO_PIN_13 | GPIO_PIN_14 | GPIO_PIN_15);
    gpio_output_options_set(GPIOE, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_7 | GPIO_PIN_8 | GPIO_PIN_9 | GPIO_PIN_10 |
                            GPIO_PIN_11 | GPIO_PIN_12 | GPIO_PIN_13 | GPIO_PIN_14 | GPIO_PIN_15);

    /* configure PE2(EXMC_A23) */ 
        gpio_af_set(GPIOE, GPIO_AF_12, GPIO_PIN_2);
    gpio_mode_set(GPIOE, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_2);
    gpio_output_options_set(GPIOE, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_2);
    
        /* configure NOE NWE */
    gpio_af_set(GPIOD, GPIO_AF_12, GPIO_PIN_4 | GPIO_PIN_5);
    gpio_mode_set(GPIOD, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_4 | GPIO_PIN_5);
    gpio_output_options_set(GPIOD, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_4 | GPIO_PIN_5);


        /* configure EXMC NE0 */
    gpio_af_set(GPIOD, GPIO_AF_12, GPIO_PIN_7);
    gpio_mode_set(GPIOD, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_7);
    gpio_output_options_set(GPIOD, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_7);

    lcd_timing_init_struct.asyn_access_mode = EXMC_ACCESS_MODE_A;
    lcd_timing_init_struct.syn_data_latency = EXMC_DATALAT_2_CLK;
    lcd_timing_init_struct.syn_clk_division = EXMC_SYN_CLOCK_RATIO_2_CLK;
    lcd_timing_init_struct.bus_latency = 0;
    lcd_timing_init_struct.asyn_data_setuptime = 7;
    lcd_timing_init_struct.asyn_address_holdtime = 2;
    lcd_timing_init_struct.asyn_address_setuptime = 5;

    lcd_init_struct.norsram_region = EXMC_BANK0_NORSRAM_REGION0;
    lcd_init_struct.write_mode = EXMC_ASYN_WRITE;
    lcd_init_struct.extended_mode = DISABLE;
    lcd_init_struct.asyn_wait = DISABLE;
    lcd_init_struct.nwait_signal = DISABLE;
    lcd_init_struct.memory_write = ENABLE;
    lcd_init_struct.nwait_config = EXMC_NWAIT_CONFIG_BEFORE;
    lcd_init_struct.wrap_burst_mode = DISABLE;
    lcd_init_struct.nwait_polarity = EXMC_NWAIT_POLARITY_LOW;
    lcd_init_struct.burst_mode = DISABLE;
    lcd_init_struct.databus_width = EXMC_NOR_DATABUS_WIDTH_16B;
    lcd_init_struct.memory_type = EXMC_MEMORY_TYPE_SRAM;
    lcd_init_struct.address_data_mux = DISABLE;
    lcd_init_struct.read_write_timing = &lcd_timing_init_struct;
    lcd_init_struct.write_timing = &lcd_timing_init_struct;

    exmc_norsram_init(&lcd_init_struct);

    exmc_norsram_enable(EXMC_BANK0_NORSRAM_REGION0);
}

3.2、lcd.c

#include "gd32f4xx.h"
#include "ili9320.h"
#include "ili9320_font.h"
#include "systick.h"
#include <stdio.h>

/*!
    \brief      write data to the selected LCD register
    \param[in]  register_id: the selected register id
    \param[in]  value: the register value to be written
    \param[out] none
    \retval     none
*/

void lcd_register_write(uint16_t register_id,uint16_t value)
{
    *(__IO uint16_t *) (BANK0_LCD_C)= register_id;
    *(__IO uint16_t *) (BANK0_LCD_D)= value;
}

/*!
    \brief      read the value of LCD register
    \param[in]  register_id: the register id
    \param[out] none
    \retval     the register value
*/
uint16_t lcd_register_read(uint8_t register_id)
{
    uint16_t data;
    *(__IO uint16_t *) (BANK0_LCD_C)= register_id;
    data = *(__IO uint16_t *) (BANK0_LCD_D); 
    return  data;
}

/*!
    \brief      write command to LCD register
    \param[in]  value: the register value to be written
    \param[out] none
    \retval     none
*/
void lcd_command_write(uint16_t value)
{
    /* write 16-bit index, then write reg */
    *(__IO uint16_t *) (BANK0_LCD_D) = value;
}

/*!
    \brief      prepare to write to the LCD GRAM register(R22h)
    \param[in]  none
    \param[out] none
    \retval     none
*/
void lcd_gram_write_prepare(void)
{
    *(__IO uint16_t *) (BANK0_LCD_C) = 0x0022;
}

/*!
    \brief      write RGB code to the LCD GRAM register
    \param[in]  rgb_code: the pixel color in RGB mode (5-6-5)
    \param[out] none
    \retval     none
*/
void lcd_gram_write(uint16_t rgb_code)
{
    /* write 16-bit GRAM register */
    *(__IO uint16_t *) (BANK0_LCD_D) = rgb_code;
}

/*!
    \brief      read data from GRAM
    \param[in]  none
    \param[out] none
    \retval     GRAM value
*/
uint16_t lcd_gram_read(void)
{
  uint16_t data;
    
  /* write GRAM register (R22h) */
  *(__IO uint16_t *) (BANK0_LCD_C) = 0x0022;
  /* dummy read (invalid data) */
  *(__IO uint16_t *) (BANK0_LCD_D); 

  data = *(__IO uint16_t *) (BANK0_LCD_D); 
  return data;
}

/*!
    \brief      initialize the LCD
    \param[in]  none
    \param[out] none
    \retval     none
*/
void lcd_init(void)
{
        uint16_t i;
        uint16_t device_code;
    
        rcu_periph_clock_enable(RCU_GPIOD);
    
    gpio_mode_set(GPIOD, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_3|GPIO_PIN_6);
        gpio_bit_set(GPIOD, GPIO_PIN_3);
    
        gpio_bit_set(GPIOD, GPIO_PIN_6);
        
        gpio_bit_reset(GPIOD, GPIO_PIN_6);
        delay_1ms(200);    
      gpio_bit_set(GPIOD, GPIO_PIN_6);
      delay_1ms(200); 
    
    if(1){    /*!< if(device_code == 0x8989) */
        lcd_register_write(0x0000,0x0001);
        lcd_register_write(0x0003,0xA8A4);
        lcd_register_write(0x000C,0x0000);
        lcd_register_write(0x000D,0x080C);
        lcd_register_write(0x000E,0x2B00);
        lcd_register_write(0x001E,0x00B0);
        lcd_register_write(0x0001,0x2B3F);
        lcd_register_write(0x0002,0x0600);
        lcd_register_write(0x0010,0x0000);
        lcd_register_write(0x0011,0x6070);
        lcd_register_write(0x0005,0x0000);
        lcd_register_write(0x0006,0x0000);
        lcd_register_write(0x0016,0xEF1C);
        lcd_register_write(0x0017,0x0003);
        lcd_register_write(0x0007,0x0233);
        lcd_register_write(0x000B,0x0000);
        lcd_register_write(0x000F,0x0000);
        lcd_register_write(0x0041,0x0000);
        lcd_register_write(0x0042,0x0000);
        lcd_register_write(0x0048,0x0000);
        lcd_register_write(0x0049,0x013F);
        lcd_register_write(0x004A,0x0000);
        lcd_register_write(0x004B,0x0000);
        lcd_register_write(0x0044,0xEF00);
        lcd_register_write(0x0045,0x0000);
        lcd_register_write(0x0046,0x013F);
        lcd_register_write(0x0030,0x0707);
        lcd_register_write(0x0031,0x0204);
        lcd_register_write(0x0032,0x0204);
        lcd_register_write(0x0033,0x0502);
        lcd_register_write(0x0034,0x0507);
        lcd_register_write(0x0035,0x0204);
        lcd_register_write(0x0036,0x0204);
        lcd_register_write(0x0037,0x0502);
        lcd_register_write(0x003A,0x0302);
        lcd_register_write(0x003B,0x0302);
        lcd_register_write(0x0023,0x0000);
        lcd_register_write(0x0024,0x0000);
        lcd_register_write(0x0025,0x8000);
        lcd_register_write(0x004e,0);
        lcd_register_write(0x004f,0);
    }else{
        return;
    }
    
    for(i=50000;i>0;i--);
}

/*!
    \brief      set the cursor of LCD
    \param[in]  x: the row-coordinate
    \param[in]  y: the column-coordinate
    \param[out] none
    \retval     none
*/
void lcd_cursor_set(uint16_t x,uint16_t y)
{
    lcd_register_write(0x004e,x);
    lcd_register_write(0x004f,y);

}

/*!
    \brief      clear the LCD screen to the specified color
    \param[in]  color: specified screen color
    \param[out] none
    \retval     none
*/
void lcd_clear(uint16_t color)
{
    uint32_t index=0;
    lcd_cursor_set(0,0);
    /* prepare to write GRAM */
    lcd_gram_write_prepare();
    for(index=0;index<76800;index++){
        *(__IO uint16_t *) (BANK0_LCD_D) = color;
    }
}

/*!
    \brief      set the point according to the specified position and color
    \param[in]  x: the row-coordinate
    \param[in]  y: the column-coordinate
    \param[in]  point: specified color of the point
    \param[out] none
    \retval     none
*/
void lcd_point_set(uint16_t x,uint16_t y,uint16_t point)
{
    if ((x > 240)||(y > 320)){
        return;
    }
    lcd_cursor_set(x,y);
    lcd_gram_write_prepare();
    lcd_gram_write(point);
}

/*!
    \brief      get point GRAM according to the specified position
    \param[in]  x: the row-coordinate
    \param[in]  y: the column-coordinate
    \param[out] none
    \retval     GRAM value of point 
*/
uint16_t lcd_point_get(uint16_t x,uint16_t y)
{
    uint16_t data;
    
    if ((x > 240)||(y > 320)){
        return 0;
    }
    
    lcd_cursor_set(x,y);
    data = lcd_gram_read();

    return  data;
}

/*!
    \brief      set window area
    \param[in]  start_x: the start position of row-coordinate
    \param[in]  start_y: the start position of column-coordinate
    \param[in]  end_x: the end position of row-coordinate
    \param[in]  end_y: the end position of column-coordinate
    \param[out] none
    \retval     none
*/
void lcd_windows_set(uint16_t start_x,uint16_t start_y,uint16_t end_x,uint16_t end_y)
{
    lcd_cursor_set(start_x, start_y);

    lcd_register_write(0x0050, start_x);
    lcd_register_write(0x0052, start_y);
    lcd_register_write(0x0051, end_x);
    lcd_register_write(0x0053, end_y);
}

/*!
    \brief      draw a horizontal line on LCD screen
    \param[in]  x: the row-coordinate
    \param[in]  start_y: the start column-coordinate
    \param[in]  end_y: the end column-coordinate
    \param[in]  color: specified color of the point
    \param[in]  width: line width
    \param[out] none
    \retval     none
*/

void lcd_hline_draw(uint16_t x,uint16_t start_y,uint16_t end_y,uint16_t color,uint16_t width)
{
    uint16_t i, y;

    for (i = 0; i < width; i++) {
        uint16_t sx = x + i;

        for (y = start_y; y < end_y; y++) {
            lcd_point_set(sx, y, color);
        }
    }
}

/*!
    \brief      draw a rectangle according to the specified position and color
    \param[in]  start_x: the start position of row-coordinate
    \param[in]  start_y: the start position of column-coordinate
    \param[in]  end_x: the end position of row-coordinate
    \param[in]  end_y: the end position of column-coordinate
    \param[in]  point: specified color of the point
    \param[out] none
    \retval     none
*/
void lcd_rectangle_draw(uint16_t start_x,uint16_t start_y,uint16_t end_x,uint16_t end_y,uint16_t point)
{
    uint16_t x,y;
    x=start_x;
    y=start_y;
    /* draw four lines */
    for(x=start_x;x<end_x;x++){
        /* draw a point */
        lcd_point_set(x,y,point);
    }
    for(y=start_y;y<end_y;y++){
        lcd_point_set(x,y,point);
    }
    for(x=end_x;x>start_x;x--){
        lcd_point_set(x,y,point);
    }
    for(y=end_y;y>start_y;y--){
        lcd_point_set(x,y,point);
    }
}

/*!
    \brief      fill the specified color to a rectangle
    \param[in]  start_x: the start position of row-coordinate
    \param[in]  start_y: the start position of column-coordinate
    \param[in]  end_x: the end position of row-coordinate
    \param[in]  end_y: the end position of column-coordinate
    \param[in]  color: specified color
    \param[out] none
    \retval     none
*/
void lcd_rectangle_fill(uint16_t start_x,uint16_t start_y,uint16_t end_x,uint16_t end_y,uint16_t color)
{
    uint16_t x, y;
    x = start_x;
    y = start_y;

    for (x = start_x; x < end_x; x++) {
        for (y = start_y; y < end_y; y++) {
            lcd_point_set(x, y, color);
        }
    }
}

/*!
    \brief      draw a picture on LCD screen according to the specified position
    \param[in]  start_x: the start position of row-coordinate
    \param[in]  start_y: the start position of column-coordinate
    \param[in]  end_x: the end position of row-coordinate
    \param[in]  end_y: the end position of column-coordinate
    \param[in]  pic: the picture pointer
    \param[out] none
    \retval     none
*/
void lcd_picture_draw(uint16_t start_x,uint16_t start_y,uint16_t end_x,uint16_t end_y,uint16_t *pic)
{
    uint32_t i, total;
    uint16_t *picturepointer = pic;
    uint16_t x,y;

    x = start_x;
    y = start_y;

    total = (end_x - start_x + 1) * (end_y - start_y + 1);
    
    for(i = 0; i < total; i ++){
        /* set point according to the specified position and color */
        lcd_point_set(x,y,*picturepointer++);
        x++;
        if(x > end_x){
            y++;
            x = start_x;
        }
    }
}

/*!
    \brief      display a char on LCD screen according to the specified position
    \param[in]  x: the start position of row-coordinate
    \param[in]  y: the start position of column-coordinate
    \param[in]  c: the char
    \param[in]  char_color: the color of char
    \param[in]  c_format: the struct of char format
                  font: CHAR_FONT_8_16 or CHAR_FONT_16_24
                  direction: CHAR_DIRECTION_HORIZONTAL or CHAR_DIRECTION_VERTICAL
                  char_color: the color of char
                  bk_color: the color of backgroud
    \param[out] none
    \retval     none
*/
void lcd_char_display(uint16_t x,uint16_t y,uint8_t c,char_format_struct c_format)
{
    uint16_t i = 0, j = 0;
    uint8_t temp_char = 0;
    uint16_t temp_char_16 = 0;
    
    if(CHAR_FONT_8_16 == c_format.font){ /* 8x16 ASCII */
        for (i = 0; i < 16; i++) {
            temp_char = ascii_8x16[((c - 0x20) * 16) + i];
            if(CHAR_DIRECTION_HORIZONTAL == c_format.direction){
                for (j = 0; j < 8; j++) {
                    if (((temp_char >> (7 - j)) & 0x01) == 0x01) {
                        /* set point of char */
                        lcd_point_set(x - i, y + j, c_format.char_color);
                    } else {
                        /* set point of background */
                        lcd_point_set(x - i, y + j, c_format.bk_color);
                    }
                }
            }else{
                for (j = 0; j < 8; j++) {
                    if (((temp_char >> (7 - j)) & 0x01) == 0x01) {
                        /* set point of char */
                        lcd_point_set(x + j, y + i, c_format.char_color);
                    } else {
                        /* set point of background */
                        lcd_point_set(x + j, y + i, c_format.bk_color);
                    }
                }
            }
        }
    }else if(CHAR_FONT_16_24 == c_format.font){ /* 16x24 ASCII */
        for (i = 0; i < 24; i++) {
            temp_char_16 = ASCII_Table_16x24[((c - 0x20) * 24) + i];
            if(CHAR_DIRECTION_HORIZONTAL == c_format.direction){
                for (j = 0; j < 16; j++) {
                    if (((temp_char_16 >> j) & 0x01) == 0x01) {
                        /* set point of char */
                        lcd_point_set(x - i, y + j, c_format.char_color);
                    } else {
                        /* set point of background */
                        lcd_point_set(x - i, y + j, c_format.bk_color);
                    }
                }
            }else{
                for (j = 0; j < 16; j++) {
                    if (((temp_char_16 >> j) & 0x01) == 0x01) {
                        /* set point of char */
                        lcd_point_set(x + j, y + i, c_format.char_color);
                    } else {
                        /* set point of background */
                        lcd_point_set(x + j, y + i, c_format.bk_color);
                    }
                }
            }
        }
    }
}

3.3、main.c

#include "gd32f4xx.h"
//#include "gd32f427v_start.h"
#include "systick.h"
#include <stdio.h>

#include "usart.h"
#include "exmc_lcd.h"
#include "ili9320.h"
#include "picture.h"


char_format_struct char_format;
uint8_t gd_website_string[]={"www.gigadevice.com"} ;



int main(void)
{
    
        uint16_t i;
    /* configure systick */
    systick_config();
    
        init_usart();
        exmc_lcd_init();
    
        lcd_init();
        lcd_clear(WHITE);
        lcd_picture_draw(40,100,40+160-1,100+87-1,(uint16_t *)(picture + BMP_HEADSIZE));
        lcd_rectangle_draw(10,10,230,310,BLUE);
    
        /* configure char format */
    char_format.char_color = BLUE;
    char_format.bk_color = WHITE;
    char_format.direction = CHAR_DIRECTION_VERTICAL;
    char_format.font = CHAR_FONT_8_16;
    
    /* draw character on LCD screen */
    for (i = 0; i < sizeof(gd_website_string)-1; i++){
        lcd_char_display((50+8*i), 180+20, *(gd_website_string+i),char_format);
    }
    
    /* enable the LEDs GPIO clock */
    rcu_periph_clock_enable(RCU_GPIOA);
        rcu_periph_clock_enable(RCU_GPIOC);

    /* configure LED2 GPIO port */
    gpio_mode_set(GPIOC, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_6);
    gpio_output_options_set(GPIOC, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_6);
    /* reset LED2 GPIO pin */
    gpio_bit_reset(GPIOC, GPIO_PIN_6);
      //PA9/PA10
        gpio_mode_set(GPIOA, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_9);
      gpio_mode_set(GPIOA, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_10);
    gpio_output_options_set(GPIOA, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_9);
        gpio_output_options_set(GPIOA, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_10);

    while(1) {
        /* turn on LED2 */
        gpio_bit_set(GPIOC, GPIO_PIN_6);
                gpio_bit_set(GPIOA, GPIO_PIN_9);
              gpio_bit_reset(GPIOA, GPIO_PIN_10);
                //lcd_register_write(0x0000,0x5555);
        delay_1ms(200);

        /* turn off LED2 */
              gpio_bit_reset(GPIOA, GPIO_PIN_9);
                gpio_bit_set(GPIOA, GPIO_PIN_10);
        gpio_bit_reset(GPIOC, GPIO_PIN_6);
                //lcd_register_write(0x0000,0xFFFF);
        delay_1ms(200);
            
              printf("a usart transmit test example!\r\n");
    }
}

屏幕显示

屏幕上显示GD的logo
20221218225106.jpg

推荐阅读
关注数
10711
内容数
187
中国高性能通用微控制器领域的领跑者兆易创新GD系列芯片技术专栏。
目录
极术微信服务号
关注极术微信号
实时接收点赞提醒和评论通知
安谋科技学堂公众号
关注安谋科技学堂
实时获取安谋科技及 Arm 教学资源
安谋科技招聘公众号
关注安谋科技招聘
实时获取安谋科技中国职位信息