嵌入式栏目

TQ2440 按键裸机驱动

根据TQ2440的手册可知KEY1、2、3、4分别由GPF1、4、2、0控制。
程序的步骤为：
1、先将GPB1、4、2、0设为输入；
2、若有按键按下则对应引脚为0，否则为1.

程序如下：
文件名 crt0.S

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.text
.global _start
_start:
        ldr r0, =0x56000010 @WATCHDOG
        mov r1, #0
        str r1, [r0]
        ldr sp, =1024*4
        bl main

halt_loop:
        b halt_loop

文件名 gpio.h

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#ifndef _GPIO_H
#define _GPIO_H

#define GPACON (*(volatile unsigned int*)0x56000000)
#define GPADAT (*(volatile unsigned int*)0x56000004)

#define GPBCON (*(volatile unsigned int*)0x56000010)
#define GPBDAT (*(volatile unsigned int*)0x56000014)
#define GPBUP  (*(volatile unsigned int*)0x56000018)

#define GPCCON (*(volatile unsigned int*)0x56000020)
#define GPCDAT (*(volatile unsigned int*)0x56000024)
#define GPCUP  (*(volatile unsigned int*)0x56000028)


#define GPDCON (*(volatile unsigned int*)0x56000030)
#define GPDDAT (*(volatile unsigned int*)0x56000034)
#define GPDUP  (*(volatile unsigned int*)0x56000038)

#define GPECON (*(volatile unsigned int*)0x56000040)
#define GPEDAT (*(volatile unsigned int*)0x56000044)
#define GPEUP  (*(volatile unsigned int*)0x56000048)

#define GPFCON (*(volatile unsigned int*)0x56000050)
#define GPFDAT (*(volatile unsigned int*)0x56000054)
#define GPFUP  (*(volatile unsigned int*)0x56000058)

#define GPGCON (*(volatile unsigned int*)0x56000060)
#define GPGDAT (*(volatile unsigned int*)0x56000064)
#define GPGUP  (*(volatile unsigned int*)0x56000068)

#define GPHCON (*(volatile unsigned int*)0x56000070)
#define GPHDAT (*(volatile unsigned int*)0x56000074)
#define GPHUP  (*(volatile unsigned int*)0x56000078)

#define GPJCON (*(volatile unsigned int*)0x560000d0)
#define GPJDAT (*(volatile unsigned int*)0x560000d4)
#define GPJUP  (*(volatile unsigned int*)0x560000d8)

#endif

文件名 key.c

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#include "gpio.h"

void delay()
{
    int i;
    for (i=0; i<100000; i++);
}

void main()
{
    GPFCON = 0b0011000000;
    GPFDAT = 0b10111;

    GPBCON = (0b01010101<<10);
    GPBDAT = 0b111100000;
    while(1)
    {
        if((GPFDAT & 0b10) == 0)                   //key1
        {
            GPBDAT = 0b111000000;
        }
        else if((GPFDAT & 0b10000) == 0)        //key2
        {
            GPBDAT = 0b110100000;
        }
        else if((GPFDAT & 0b100) == 0)          //key3
        {
            GPBDAT = 0b101100000;
        }
        else if((GPFDAT & 0b1) == 0)            //key4
        {
            GPBDAT = 0b011100000;
        }
        else continue;
        delay();
        GPBDAT = 0b111100000;
    }
}

文件名 Makefile

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ARCH = arm-linux-
CC = $(ARCH)gcc
LD = $(ARCH)ld
OBJDUMP = $(ARCH)objdump
OBJCOPY = $(ARCH)objcopy

all: crt0.S key.c
	$(CC) -nostdlib -g -c -o crt0.o crt0.S
	$(CC) -nostdlib -g -c -o key.o key.c
	$(LD) -Ttext 0x00000000 -g crt0.o key.o -o key-elf
	$(OBJCOPY) -O binary -S key-elf key_c.bin
	$(OBJDUMP) -D -m arm key-elf &gt; key.dis

clean:
	rm -f *.o key-elf key_c.bin key.dis