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