EX_CCP1S.C
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/////////////////////////////////////////////////////////////////////////
//// EX_CCP1S.C ////
//// ////
//// This program will show how to use the built in CCP to ////
//// generate a single pulse of a predefined time in response ////
//// to a pushbutton (40). ////
//// ////
//// Configure the CCS prototype card as follows: ////
//// Connect a scope to pin 3 (C2) ////
//// Connect 40 (button) to 47 (B0) ////
//// ////
//// This example will work with the PCM and PCH compilers. The ////
//// following conditional compilation lines are used to include a ////
//// valid device for each compiler. Change the device and clock ////
//// for your hardware if needed. ////
/////////////////////////////////////////////////////////////////////////
//// (C) Copyright 1996,2001 Custom Computer Services ////
//// This source code may only be used by licensed users of the CCS ////
//// C compiler. This source code may only be distributed to other ////
//// licensed users of the CCS C compiler. No other use, ////
//// reproduction or distribution is permitted without written ////
//// permission. Derivative programs created using this software ////
//// in object code form are not restricted in any way. ////
/////////////////////////////////////////////////////////////////////////
#if defined(__PCM__)
#include <16c74.h>
#fuses HS,NOWDT,NOPROTECT
#use delay(clock=20000000)
#elif defined(__PCH__)
#include <18c452.h>
#fuses HS,NOPROTECT
#use delay(clock=20000000)
#endif
main() {
setup_ccp1(CCP_COMPARE_CLR_ON_MATCH); // Configure CCP1 in COMPARE mode
setup_timer_1(T1_INTERNAL); // Set up timer to instruction clk
while(TRUE) {
while(input(PIN_B0)) ; // Wait for keypress
setup_ccp1(CCP_COMPARE_SET_ON_MATCH); // Configure CCP1 to set
CCP_1=0; // C2 high now
set_timer1(0);
CCP_1 = 500; // Set high time limit
// to 100 us
// limit is time/(clock/4)
// 500 = .0001*(20000000/4)
setup_ccp1(CCP_COMPARE_CLR_ON_MATCH); // Configure CCP1 in COMPARE
// mode and to pull pin C2
// low on a match with timer1
delay_ms(1000); // Debounce - Permit only one pulse/sec
}
}
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