//-----------------------------------------------------------------------------
// F02x_External_Interrupts.c
//-----------------------------------------------------------------------------
// Copyright 2007 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// 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 P3.7 (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
//
// P1.6 - LED
//
// P3.7 - SWITCH
//
// How To Test:
//
// 1) Compile and download code to a 'F02x target board.
// 2) On the target board, connect the switch side of J1 to either P0.0 for
// /INT0 or P0.1 for /INT1.
// 3) Verify the J3 jumper is in place.
// 4) Verify the J6 and J9 jumpers are removed.
// 5) Press the P3.7 switch. Every time the switch is pressed, the P1.6 LED
// should toggle.
//
// Target: C8051F02x
// Tool chain: Keil C51 7.50 / Keil EVAL C51
// Command Line: None
//
//
// Release 1.0
// -Initial Revision (SM)
// -19 JUN 2007
//
//-----------------------------------------------------------------------------
// Include Files
//-----------------------------------------------------------------------------
#include <C8051F020.h>
//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------
#define SYSCLK (22118400L)
sbit LED = P1^6; // Green Led
sbit SWITCH = P3^7; // Push-button switch on board
//-----------------------------------------------------------------------------
// Function Prototypes
//-----------------------------------------------------------------------------
void Oscillator_Init (void); // Configure the system clock
void Port_Init (void); // Configure the Crossbar and GPIO
void Ext_Interrupt_Init (void); // Configure External Interrupts (/INT0
// and /INT1)
//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
void main (void)
{
WDTCN = 0xDE; // Disable Watchdog timer
WDTCN = 0xAD;
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 function initializes the system clock to use the external 22.1184MHz
// crystal.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
int i; // Software timer
OSCICN |= 0x80; // Enable the missing clock detector
// Initialize external crystal oscillator to use 22.1184 MHz crystal
OSCXCN = 0x67; // Enable external crystal osc.
for (i=0; i < 256; i++); // Wait at least 1ms
while (!(OSCXCN & 0x80)); // Wait for crystal osc to settle
OSCICN |= 0x08; // Select external clock source
OSCICN &= ~0x04; // Disable the internal osc.
}
//-----------------------------------------------------------------------------
// 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
//
// P1.6 - digital push-pull LED
//
// P3.7 - digital open-drain SWITCH
//
//-----------------------------------------------------------------------------
void Port_Init (void)
{
XBR0 = 0x00;
XBR1 = 0x14; // No peripherals selected
XBR2 = 0x40; // Enable crossbar and weak pullups
P1MDOUT = 0x40; // LED is push-pull a output
}
//-----------------------------------------------------------------------------
// 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 falling edge
// triggered
EX0 = 1; // Enable /INT0 interrupts
EX1 = 1; // Enable /INT1 interrupts
}
//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// /INT0 ISR
//-----------------------------------------------------------------------------
//
// Whenever a negative edge appears on P0.0, the LED is toggled.
// The interrupt pending flag is automatically cleared by vectoring to the ISR
//
//-----------------------------------------------------------------------------
void INT0_ISR (void) interrupt 0
{
LED = !LED;
}
//-----------------------------------------------------------------------------
// /INT1 ISR
//-----------------------------------------------------------------------------
//
// Whenever a negative edge appears on P0.1, the LED is toggled.
// The interrupt pending flag is automatically cleared by vectoring to the ISR
//
//-----------------------------------------------------------------------------
void INT1_ISR (void) interrupt 2
{
LED = !LED;
}
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------
