main.cpp

00001 /*Program Example 14.1: Sets up a digital output pin using control registers, and flashes an led.
00002                                                                          */
00003 // function prototypes
00004 void delay(void);
00005 
00006 //Define addresses of digital i/o control registers, as pointers to volatile data
00007 #define FIO2DIR0       (*(volatile unsigned char *)(0x2009C040))
00008 #define FIO2PIN0       (*(volatile unsigned char *)(0x2009C054))
00009 #define FIO0PIN0 (*( volatile unsigned char *)(0x2009C014))
00010 
00011 int main()
00012 {
00013     FIO2DIR0=0xFF;     // set port 2, lowest byte to output
00014     while(1) {
00015         for (int i=1; i<=3; i++) {
00016             FIO0PIN0 |= 0x02;       // set port 2 pin 1 high (mbed pin 25)
00017             delay();
00018             FIO0PIN0 &= ~0x02;      // set port 2 pin 1 low
00019             delay();
00020         }
00021 
00022     }
00023 }
00024 //delay function
00025 void delay(void)
00026 {
00027     int j;                      //loop variable j
00028     for (j=0; j<1000000; j++) {
00029         j++;
00030         j--;                      //waste time
00031     }
00032 }
00033 
00034