Write a program to toggle LED3 on STM32 board every 500 ms
The system timer registers base address is 0xE000E010
| Offset | Register |
| 0 | Control |
| 4 | Load |
| 8 | Value |
| 12 | Calibrate |
Notes:
- The CPU frequency is 24MHz (24000000 ticks/sec)
- The timer is 24bits (max load value = 0xffffff)
- Define the ISR as void (*)(void)
- For more information read the chip manual
Change your program to toggle the LED every 2 seconds