C8051F410外部中断历程.doc

/-/ F41x_External_Interrupts.c/-/ Copyright 2007 Silicon Laboratories, Inc./ / Program Description:/ This software shows the necessary configuration to use External Interrupt 0/ (/INT0) or External Interrupt 1 (/INT1) as an interrupt source. The code/ executes the initialization routines and then spins in an infinite while()/ loop. If the button on P1.4 (on the target board) is pressed, then the/ edge-triggered /INT0 input on P0.0 will cause an interrupt and toggle the/ LED./ Pinout:/ P0.0 - /INT0/ P0.1 - /INT1/ P1.4 - SW1 (Switch 1)/ P1.5 - SW2 (Switch 2)/ P2.1 - LED1/ P2.3 - LED2/ How To Test:/ 1) Compile and download code to a F41x target board./ 2) On the target board, connect P1.4 and P1.5 signals on J5 to P0.0/ for /INT0 and P0.1 for /INT1./ 3) Press the switches. Every time a switch is pressed, the P2.1 or P2.3/ LED should toggle./ Target: C8051F41x/ Tool chain: Keil C51 7.50 / Keil EVAL C51/ Command Line: None/ Release 1.0/ -Initial Revision (SM)/ -19 JUN 2007/-/ Include Files/-#include /-/ Global Constants/-#define SYSCLK 24500000 / Clock speed in Hzsbit SW1 = P14; / Push-button switch on boardsbit SW2 = P15; / Push-button switch on boardsbit LED1 = P21; / Green LEDsbit LED2 = P23; / Green LED/-/ Function Prototypes/-void Oscillator_Init (void); / Configure the system clockvoid Port_Init (void); / Configure the Crossbar and GPIOvoid Ext_Interrupt_Init (void); / Configure External Interrupts (/INT0 / and /INT1)/-/ MAIN Routine/-void main (void) PCA0MD &= 0x40; / Disable Watchdog timer Oscillator_Init(); / Initialize the system clock Port_Init (); / Initialize crossbar and GPIO Ext_Interrupt_Init(); / Initialize External Interrupts EA = 1; while(1); / Infinite while loop waiting for / an interrupt from /INT0 or /INT1/-/ Initialization Subroutines/-/-/ Oscillator_Init/-/ Return Value : None/ Parameters : None/ This routine initializes the system clock to use the precision internal/ oscillator as its clock source./-void Oscillator_Init (void) OSCICN = 0x87; / Set internal oscillator to run / at its maximum frequency/-/ Port_Init/-/ Return Value : None/ Parameters : None/ This function configures the crossbar and GPIO ports./ Pinout:/ P0.0 - digital open-drain /INT0/ P0.1 - digital open-drain /INT1/ P1.4 - digital open-drain SW1 (Switch 1)/ P1.5 - digital open-drain SW2 (Switch 2)/ P2.1 - digital push-pull LED1/ P2.3 - digital push-pull LED2/-void Port_Init (void) XBR1 = 0x40; / Enable crossbar and weak pullups P2MDOUT = 0x0A; / LED1 and LED2 are push-pull outputs/-/ Ext_Interrupt_Init/-/ Return Value : None/ Parameters : None/ This function configures and enables /INT0 and /INT1 (External Interrupts)/ as negative edge-triggered./-void Ext_Interrupt_Init (void) TCON = 0x05; / /INT 0 and /INT 1 are edge triggered IT01CF = 0x10; / /INT0 active low; /INT0 on P0.0; / /INT1 active low; /INT1 on P0.1 EX0 = 1; / Enable /INT0 interrupts EX1 = 1; / Enable /INT1 interrupts/-/ Interrupt Service Routines/-/-/ /INT0 ISR/-/ Whenever a negative edge appears on P0.0, LED1 is toggled./ The interrupt pending flag is automatically cleared by vectoring to the ISR/-void INT0_ISR (void) interrupt 0 LED1 = !LED1;/-/ /INT1 ISR/-/ Whenever a negative edge appear