upgrading a FIRMWARE on Atmega64a microcontroller.

Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
uint8_t buf[256];
int page= 0x0000;
#define SPM_PAGESIZE 256
int pos=0;
 
void boot_program_page (uint32_t page, uint8_t *buf)
{
        uint16_t i;
        cli();   // Disable interrupts.
 
        boot_page_erase (page);         
        boot_spm_busy_wait ();    // Wait until the memory is erased.
 
        for (i=0; i<SPM_PAGESIZE; i+=2)
        {
                /*uint16_t w = *buf++;
                  w += (*buf++) << 8;*/
 
                boot_page_fill (page + i,buf[i]);
        }
        boot_page_write (page);
        boot_spm_busy_wait();
        sei();  //enable interrupts
}
 
 
 
/***************************** main **********************************************/
 
int main(void)
{
     void (*funcptr)( void ) = 0x0000; // Set up function pointer to RESET vector.
     
     inituart(); // Initialize UART.
     _delay_ms(4000);
     start_timer(4);
     while(!(timer_expired) && (pos<128))
     {
         recchar();
     }
     stop_timer();
 
     if(pos > 0)                   
     {                        //if rx data enter in BLS.
        boot_program_page(page, buf);     
     }
     else
     {
            boot_spm_busy_wait();
            boot_rww_enable ();
            funcptr(); // Jump to Reset vector 0x0000 in Application Section.
         }
 return 0;
}
 
// receiving data through UART.
 
               
unsigned char recchar(void)
{  
  while(!(UART_STATUS_REG & (1 << RECEIVE_COMPLETE_BIT)));  // wait for data
 
   buf[pos++]=UART_DATA_REG;
   return 0;
}