实验五

code unsigned char position[6]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf};
unsigned char dis_buff[6]; // 显示缓冲区，存放要显示的个字符的段码值
unsigned int icp_v1,icp_v2;
unsigned char icp_n,max_icp;
P0 = 0xFF;
P1 = led_7[dis_buff[posit]];
P0 = position[posit];
if (++posit >=4) posit = 0;
}
void Timer2_Init(void) //产生ms 的定时周期，用于LED 扫描
OSCICN |= 0x04; // Force Internal Osc. 1:8 prescaler
while ((OSCICN & 0x40 ) == 0); // Wait until stable
P0MDOUT = 0xFF;
P1MDOUT = 0xFF;
P2MDOUT = 0x08;
CR = 1;
TR0 = 1;
}
void PCA0_ISR (void) interrupt 11
{
if (CCF0)
{
if (icp_n >= max_icp) // 第N 个上升沿到
{
icp_v2 = PCA0CP0; // 记录第N 个上升沿时间
TMR2 = TMR2RL;
TMR2CN |= 0x04; //Start Timer3
ET2 = 1; // Timer2 interrupt enabled
{
if(dis_buff[i]==0)
dis_buff[i]=10;
else
break;
}
}
void display(void) // 6 位LED 数管动态扫描函数
{
unsigned char posit; // 秒显示标志
void f_to_disbuf(long v) // 频率值送显示缓冲区函数,且高位零不显示
{
unsigned char i ;
for(i=0;i<=4;i++)
{
dis_buff[i]=v%10;
v=v/10;
}
dis_buff[5]=v;
for(i=5;i>0;i--)
{
TMR2CN &= ~0x08; // Enable Timer2 in 16 auto-reload mode
CKCON |= 0x10; // Timer2 uses SYSCLK
TMR2RL = -(TIMER_TICKS_PER_MS*TIMER_TICKS_MS);
{
if (f_2_d)
{
f_to_disbuf(fv); // 新频率送显示
f_2_d = 0;
}
else if (begin_m)
{
icp_n = 0; // 开始新的一次测量，
full_ok = 0; // 清除溢出标志
EIE1 |= 0x10; // 开启输入捕捉、溢出中断允许
if (!(icp_v2 >= icp_v1 && full_ok)) // 有溢出，数据无效
{
if (icp_2 == icp_1) // 两次个数相等，测量有效
{
fv = 24500000/8*(long)max_icp/icp_2; // 换算成频率值
f_2_d = 1; // 允许新频率送显示
EIE1 &= ~0x10;// 禁止输入捕捉和溢出中断
icp_ok = 1;
}
else if (icp_n == 0)
{
icp_v1=PCA0CP0;// 记录第个上升沿时间
}
icp_n++;
#include <C8051F410.h>
#define SYSCLK 24500000/8
#define TIMER_TICKS_MS 4
#define TIMER_TICKS_PER_MS SYSCLK/1000
code unsigned char led_7[11]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x00};
P0SKIP = 0xFF;
P1SKIP = 0xFF;
P2SKIP = 0x07;
XBR1 = 0x41;//交叉开关配置
Timer2_Init ();
PCA0_Init ();
EA = 1; // Enable global interrupts
icp_n = 0;
max_icp =1;
while (1)
{
if (icp_ok == 1 icp_v1) // 计算N 个上升沿的时钟脉冲个数，
icp_2 = icp_v2 - icp_v1;
else
icp_2 = 65536 - icp_v1 + icp_v2;
begin_m = 0;
}
time_4ms_ok = 0;
}
}
}
bit icp_ok,time_4ms_ok,f_2_d,begin_m,full_ok;
sfr16 PCA0CP0 = 0xFB;
sfr16 TMR2RL = 0xCA; // Timer2 Reload Register
sfr16 TMR2 = 0xCC; // Timer2 Register
{
TMOD &= 0xF0;
TMOD |= 0x02;
CKCON |= 0x04;
TH0 = -1;
TL0 = -1;
PCA0CN = 0x00;
PCA0MD = 0x05;
PCA0CPM0 = 0x21;
EIE1 |= 0x10;
if (fv > 4000)
max_icp = 64; // 如果频率大于Khz，N=64
else
max_icp = 1; // N=1
}
}
else
max_icp = 1; // 有溢出，N=1
icp_1 = icp_2;
icp_ok = 0;
begin_m = 1;
}
if (time_4ms_ok)
CCF0 = 0;
}
if (CF)
{
full_ok = 1;
CF = 0;
}
}
void main (void)
{
unsigned int icp_1,icp_2;
long fv;
PCA0MD &= ~0x40; // Clear watchdog timer enable
}
void Timer2_ISR (void) interrupt 5
{
display();
time_4ms_ok = 1;
TF2H = 0;
}
void PCA0_Init (void) //T0 8 位自动重装, 定时周期(8/24.5 us)，PCA 使用T0 作为时基