#在Avr Studio 5(ATmega16)中定义PORTX.x
问题描述:
我正在为KS0108 GLCD驱动程序编写全新的专用库,并提供新的算法和功能。我正在使用ATMega16。我的点阵GLCD尺寸是128x64。#在Avr Studio 5(ATmega16)中定义PORTX.x
如何使用#define代码定义不同的端口引脚?
例如:的#define GLCD_CTRL_RESTART PORTC.0
IDE:AVR工作室5
语言:Ç
模块:128X64点阵GLCD
司机:KS0108
微控制器:ATMega16
请解释我应该使用哪些标题?并且为ATMEga16写一个完整且非常简单的代码。
答
在ATmega中,引脚值汇编在PORT寄存器中。一个引脚值是一个PORT中某个位的值。 ATmega没有像其他一些处理器那样的可寻址IO内存,所以你不能像你所建议的那样用一个#define
来引用一个引脚来读写。
如果可以帮助你,你可以做的是定义宏来读取或写入引脚值。您可以更改宏的名称以满足您的需求。
#include <avr/io.h>
#define PORTC_BIT0_READ() ((PORTC & _BV(PC0)) >> PC0)
#define WRITE_PORTC_BIT0(x) (PORTC = (PORTC & ~_BV(PC0)) | ((x) << PC0))
uint8_t a = 1, b;
/* Change bit 0 of PORTC to 1 */
WRITE_PORTC_BIT0(a);
/* Read bit 0 of PORTC in b */
b = PORTC_BIT0_READ();
答
非常感谢,但是我发现在AVR单片机这个答案在here:
BV =位值。
If you want to change the state of bit 6 in a byte you can use _BV(6) which is is equivalent to 0x40. But a lot us prefer the completely STANDARD method and simply write (1<<6) for the same thing or more specifically (1<<<some_bit_name_in_position_6)
For example if I want to set bit 6 in PORTB I'd use:
Code:
PORTB |= (1 << PB6);
though I guess I could use:
Code:
PORTB |= _BV(6);
or
Code:
PORTB |= _BV(PB6);
But, like I say, personally I'd steer clear of _BV() as it is non standard and non portable. After all it is simply:
Code:
#define _BV(n) (1 << n)
anyway.
Cliff