cfsk.h

DTMF FSK 在51 上的实现

#ifndef _CFSK_H
#define _CFSK_H
    //cfsk bit define 1:1270hz, 0:1070hz
    #define PERIOD_970HZ  0x407   //970hz    1 cycle period
	#define PERIOD_1170HZ 0x356   //1170hz   1 cycle period
	#define PERIOD_1370HZ 0x2DA   //1370hz   1 cycle period
	#define COUNT_1170    57      //;This is the number of events that will
				                  //;occur in 50ms @ 1170hz. (1/15/93)

    #define COUNT_1370    74      //  ;This is the number of events that will
    				              //;occur in 50ms @ 1370hz.(1/15/93)

    #define COUNT_2150    700     //   ;This is the number of events that will
    				              // ;occur in 350ms @ 2000hz.

    				              //;occur in 350ms @ 2600hz.

	#define period_start_low   0x081D  //1925Hz, 4 cycle start bit detect ---BORIS
    //varible declaration
    extern bit DTMF_process_flag,CFSK_process_flag;
	extern bit DTMF_1ms_timer,DTMF_capture_timer,CEX2_first_period;
    extern unsigned char PCA_buf0_high,PCA_buf0_low,PCA_buf1_high,PCA_buf1_low;
    extern unsigned int  received_tone;

    void CFSK_process(void);

    extern dial_the_receiver(void);// dialing routine in DTMF.c
	extern unsigned int DTMF_1ms_count;
#endif
    #define COUNT_2450    910 //  ;This is the number of events that will