基于OK6410的触摸屏驱动

对于touch screem的使用：

3. Auto(Sequential) X/Y Position Conversion Mode (AUTO_PST=1, XY_PST=0)

Auto (Sequential) X/Y Position Conversion Mode is operated in the following method: Touch screen controller

sequentially converts X-Position and Y-Position that is touched. After Touch screen controller writes Xmeasurement

data to ADCDAT0 and writes Y-measurement data to ADCDAT1, Touch screen interface

generates Interrupt (INT_ADC). The measurement states are automatically changed. When X-Position is

detected, XP and XM switch is automatically on and ADC channel selection bits are automatically changed

to ’5’. And then when X-Position is detected, YP and YM switch is automatically on and ADC channel selection

bits are automatically changed to ’7’. After Auto X/Y position conversion, mode is changed for pull-up interrupt

detection (ADCTSC = 0x173)

首先pen down；

检测到中断，清标志位

启动AD转换，确定x/y位置

清AD中断

等待pen up

检测到中断，清标志位

做一些我们想要的操作

恢复到等待pen down的模式

对于触摸屏的初始化有三步

1.设置ADC转化要用的时钟

2.配置中断允许和清除标志位

3.进入等待中断模式

在ADCCON中设置

[16]使用10bitAD转化；[15]只读，用来读取AD转化是否完成；[14]使能AD预分频；[13:6]设置AD预分频，保证AD的时钟频率小于PCLK的1/5，我们PCLK为50MHz，所以我们用1MHz，填入49；

void ts_init()

{

ADCCON=(1<<14)|(49<<6);

ADCCLRINT=0; //清除ADC中断

ADCCLRINTPNDNUP=0; //清除pen中断

ADCDLY=0xffff; //ADC Start or Interval Delay Register，为ADC转化延时

VIC1INTENABLE=(0b1<<30); //使能ADC关于pen的中断

ADCTSC=0xd3; //进入等待pen中断的模式

}

在中断处理文件里面往VIC1VECTADDR30地址添加中断处理函数，即执行ts_handler

Note: 1) While waiting for Touch screen Interrupt, XP_SEN bit must be set to ‘1’, namely ‘Switch disable’

and PULL_UP bit must be set to ‘0’, namely ‘XP Pull-up enable’.

2) AUTO_PST bit should be set ‘1’ only in Automatic & Sequential X/Y Position conversion.

3) If you don’t use AIN[7], you must tie AIN [7] to VDDA_ADC or ADCTSC register must be setting to 0xd3.

void ts_handler()

{

//clear the IFs

ADCUPDN=0; //进入中断处理函数后先通过特殊的寄存器清除中断标记（这里比较特殊，通过配置寄存器清除中断标志位），这三个寄存器

ADCCLRINT=0;

ADCCLRINTPNDNUP=0;

VIC0ADDRESS=0; //清除中断

VIC1ADDRESS=0;

ADCTSC=(1<<2); //进入AD转换，并且自动区分x/y

ADCCON=(0b1<<0)|(1<<14)|(49<<6); //开始AD转换

while(!((ADCCON>>15)&1)); //等待AD转换完成（通过检测ADCCON的第15位）

xdat=ADCDAT0&0x3ff; //在ADCDAT0和ADCDAT1中的最低10位读取x/y值

ydat=ADCDAT1&0x3ff;

ADCTSC=0x1d3; //进入等待pen弹起的模式

while(1) //TC[9] 等待pen弹起

{

if((ADCUPDN>>1)&0b1)

break;

}

ADCCLRINT=0; //清除pen弹起产生的中断

ADCCLRINTPNDNUP=0;

ADCUPDN=0;

VIC0ADDRESS=0;

VIC1ADDRESS=0;

printf("\n\rx=%d , y=%d\n\r",xdat,ydat); //在串口输出x/y的位置

ADCTSC=0xd3; //恢复等待pen按下的操作，为等待下一次pen的按下

}

在这里有一个注意的是在ADCCLRINT，ADCCLRINTPNDNUP写入数据会清除中断，但是在ADCUPDN里面还会有标志位，这个寄存器是可读可写的，要把它改为0

贴上完整代码

#define ADCCON *((volatile unsigned long*)0x7E00B000)

#define ADCTSC *((volatile unsigned long*)0x7E00B004)

#define ADCDAT0 *((volatile unsigned long*)0x7E00B00C)

#define ADCDAT1 *((volatile unsigned long*)0x7E00B010)

#define ADCCLRINT *((volatile unsigned char*)0x7E00B018)

#define ADCCLRINTPNDNUP *((volatile unsigned char*)0x7E00B020)

#define ADCUPDN *((volatile unsigned char*)0x7E00B014)

#define VIC1INTENABLE *((volatile unsigned long*)0x71300010)

#define VIC0INTENABLE *((volatile unsigned long*)0x71200010)

#define ADCDLY *((volatile unsigned long*)0x7E00B008)

#define VIC0ADDRESS *((volatile unsigned long*)0x71200F00)

#define VIC1ADDRESS *((volatile unsigned long*)0x71300F00)

int xdat=0,ydat=0;

void ts_init()

{

ADCCON=(1<<14)|(49<<6);

ADCCLRINT=0;

ADCCLRINTPNDNUP=0;

ADCDLY=0xffff;

VIC1INTENABLE=(0b1<<30);

ADCTSC=0xd3;

}

void ts_handler()

{

ADCUPDN=0;

ADCCLRINT=0;

ADCCLRINTPNDNUP=0;

VIC0ADDRESS=0;

VIC1ADDRESS=0;

ADCTSC=(1<<2);

ADCCON=(0b1<<0)|(1<<14)|(49<<6);

while(!((ADCCON>>15)&1));

xdat=ADCDAT0&0x3ff;

ydat=ADCDAT1&0x3ff;

ADCTSC=0x1d3;

while(1) //TC[9]

{

if((ADCUPDN>>1)&0b1)

break;

}

ADCCLRINT=0;

ADCCLRINTPNDNUP=0;

ADCUPDN=0;

VIC0ADDRESS=0;

VIC1ADDRESS=0;

printf("\n\rx=%d , y=%d\n\r",xdat,ydat);

ADCTSC=0xd3;

}

void delay()

{

unsigned int i,j;

for(i=0;i<=100;i++)

for(j=0;j<=60;j++);

}