demo_12_3__.c

来自「CVAVR完整程序」· C语言 代码 · 共 56 行

/*****************************************************
File name	        : demo_12_3.c
Chip type           : ATmega16
Program type        : Application
Clock frequency     : 4.000000 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*****************************************************/
#include <mega16.h>
	#ifndef __SLEEP_DEFINED__
	#define __SLEEP_DEFINED__
	.EQU __se_bit=0x40
	.EQU __sm_mask=0xB0
	.EQU __sm_powerdown=0x20
	.EQU __sm_powersave=0x30
	.EQU __sm_standby=0xA0
	.EQU __sm_ext_standby=0xB0
	.EQU __sm_adc_noise_red=0x10
	.SET power_ctrl_reg=mcucr
	#endif

#define hc165_clk   PORTB.0
#define hc165_lp    PORTB.1
#define hc165_out   PINB.2

unsigned char read_hc165(void)
{
	unsigned char data = 0,i,temp = 0x80;
	hc165_lp = 0;               // 置lp低电平，读入8位并口数据
	hc165_lp = 1;               // 置lp高电平，保持数据
	for (i=0;i<=7;i++)
	{
	    if (hc165_out)          // 读入1位数据
			data |= temp;
		hc165_clk = 1;          // clk上升沿，串出下1位数据
		temp = temp >> 1;
		hc165_clk = 0;          // clk下降沿，保持
	}
    return data;
}

void main(void)
{
    PORTA=0xFF;
    DDRA=0xFF;

    PORTB=0x06;
    DDRB=0x03;

    while (1)
    {
        PORTA = ~read_hc165();  // 8位数据取反，点亮相应的LED
    }
}