#include <reg52.h>
#define LCD1602_DB P0
sbit LCD1602_RS = P1^0;
sbit LCD1602_RW = P1^1;
sbit LCD1602_E = P1^5;
bit flag500ms = 0; //500ms定时标志
unsigned char T0RH = 0; //T0重载值的高字节
unsigned char T0RL = 0; //T0重载值的低字节
//待显示的第一行字符串
unsigned char code str1[] = "Kingst Studio";
//待显示的第二行字符串，需保持与第一行字符串等长，较短的行可用空格补齐
unsigned char code str2[] = "Let's move...";
void ConfigTimer0(unsigned int ms);
void InitLcd1602();
void LcdShowStr(unsigned char x, unsigned char y,
unsigned char *str, unsigned char len);
void main()
{
unsigned char i;
unsigned char index = 0; //移动索引
unsigned char pdata bufMove1[16+sizeof(str1)+16]; //移动显示缓冲区1
unsigned char pdata bufMove2[16+sizeof(str2)+16]; //移动显示缓冲区2
EA = 1; //开总中断
ConfigTimer0(10); //配置T0定时10ms
InitLcd1602(); //初始化液晶
//缓冲区开头一段填充为空格
for (i=0; i<16; i++)
{
bufMove1[ i] = ' ';
bufMove2[ i] = ' ';
}
//待显示字符串拷贝到缓冲区中间位置
for (i=0; i<(sizeof(str1)-1); i++)
{
bufMove1[16+i] = str1[ i];
bufMove2[16+i] = str2[ i];
}
//缓冲区结尾一段也填充为空格
for (i=(16+sizeof(str1)-1); i<sizeof(bufMove1); i++)
{
bufMove1[ i] = ' ';
bufMove2[ i] = ' ';
}
while (1)
{
if (flag500ms) //每500ms移动一次屏幕
{
flag500ms = 0;
//从缓冲区抽出需显示的一段字符显示到液晶上
LcdShowStr(0, 0, bufMove1+index, 16);
LcdShowStr(0, 1, bufMove2+index, 16);
//移动索引递增，实现左移
index++;
if (index >= (16+sizeof(str1)-1))
{ //起始位置达到字符串尾部后即返回从头开始
index = 0;
}
}
}
}
/* 配置并启动T0，ms-T0定时时间 */
void ConfigTimer0(unsigned int ms)
{
unsigned long tmp; //临时变量
tmp = 11059200 / 12; //定时器计数频率
tmp = (tmp * ms) / 1000; //计算所需的计数值
tmp = 65536 - tmp; //计算定时器重载值
tmp = tmp + 12; //补偿中断响应延时造成的误差
T0RH = (unsigned char)(tmp>>8); //定时器重载值拆分为高低字节
T0RL = (unsigned char)tmp;
TMOD &= 0xF0; //清零T0的控制位
TMOD |= 0x01; //配置T0为模式1
TH0 = T0RH; //加载T0重载值
TL0 = T0RL;
ET0 = 1; //使能T0中断
TR0 = 1; //启动T0
}
/* 等待液晶准备好 */
void LcdWaitReady()
{
unsigned char sta;
LCD1602_DB = 0xFF;
LCD1602_RS = 0;
LCD1602_RW = 1;
do {
LCD1602_E = 1;
sta = LCD1602_DB; //读取状态字
LCD1602_E = 0;
} while (sta & 0x80); //bit7等于1表示液晶正忙，重复检测直到其等于0为止
}
/* 向LCD1602液晶写入一字节命令，cmd-待写入命令值 */
void LcdWriteCmd(unsigned char cmd)
{
LcdWaitReady();
LCD1602_RS = 0;
LCD1602_RW = 0;
LCD1602_DB = cmd;
LCD1602_E = 1;
LCD1602_E = 0;
}
/* 向LCD1602液晶写入一字节数据，dat-待写入数据值 */
void LcdWriteDat(unsigned char dat)
{
LcdWaitReady();
LCD1602_RS = 1;
LCD1602_RW = 0;
LCD1602_DB = dat;
LCD1602_E = 1;
LCD1602_E = 0;
}
/* 设置显示RAM起始地址，亦即光标位置，(x,y)-对应屏幕上的字符坐标 */
void LcdSetCursor(unsigned char x, unsigned char y)
{
unsigned char addr;
if (y == 0) //由输入的屏幕坐标计算显示RAM的地址
addr = 0x00 + x; //第一行字符地址从0x00起始
else
addr = 0x40 + x; //第二行字符地址从0x40起始
LcdWriteCmd(addr | 0x80); //设置RAM地址
}
/* 在液晶上显示字符串，(x,y)-对应屏幕上的起始坐标，
str-字符串指针，len-需显示的字符长度 */
void LcdShowStr(unsigned char x, unsigned char y,
unsigned char *str, unsigned char len)
{
LcdSetCursor(x, y); //设置起始地址
while (len--) //连续写入len个字符数据
{
LcdWriteDat(*str++); //先取str指向的数据，然后str自加1
}
}
/* 初始化1602液晶 */
void InitLcd1602()
{
LcdWriteCmd(0x38); //16*2显示，5*7点阵，8位数据接口
LcdWriteCmd(0x0C); //显示器开，光标关闭
LcdWriteCmd(0x06); //文字不动，地址自动+1
LcdWriteCmd(0x01); //清屏
}
/* T0中断服务函数，定时500ms */
void InterruptTimer0() interrupt 1
{
static unsigned char tmr500ms = 0;
TH0 = T0RH; //重新加载重载值
TL0 = T0RL;
tmr500ms++;
if (tmr500ms >= 50)
{
tmr500ms = 0;
flag500ms = 1;
}
}
问：bufMove1+index代入void LcdShowStr(unsigned char x, unsigned char y,
unsigned char *str, unsigned char len)的 LcdWriteDat(*str++)的流程是什么？
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20 黑币
