flashprom.c~

通过串口升级mega8的自编程例子原码

#include "define.h"
// a,b--address
unsigned char read_flash(unsigned char a,unsigned char b)
{
#asm
	.equ spmcr=0x37
	ldd r30,y+1
	ld r31,y
	lpm
	mov r30,r0
#endasm
}
// a--address
unsigned char read_fuse(unsigned char a)
{
#asm
	ld r30,y
	ldi r31,0
	ldi r22,0x09;
	out spmcr,r22
	lpm
	mov r30,r0
#endasm
}
// a,b--address c,d--data
unsigned char write_flashbuf(unsigned char a,unsigned char b,unsigned char c,unsigned char d)
{
#asm
	in r22,spmcr
	ldi r30,0
	sbrc r22,0
	rjmp wwend
	ldd r30,y+3
	ldd r31,y+2
	ldd r0,y+1
	ld r1,y
	ldi r22,0x01
	cli
	out spmcr,r22
	spm
	sei
	ldi r30,1
wwend:
#endasm
}
// 0--wait 1--finish
unsigned char erase_doing(unsigned char a,unsigned char b)//
{
#asm
	in r22,spmcr
	ldi r30,0
	sbrc r22,0
	rjmp erend
	ldd r30,y+1
	ld r31,y
	ldi r22,3
	cli
	out spmcr,r22
	spm
	sei
	ldi r30,1
erend:
#endasm
}
// 0--wait 1--finish
unsigned char write_doing(unsigned char a,unsigned char b)
{
#asm
	in r22,spmcr
	ldi r30,0
	sbrc r22,0
	rjmp wrend
	ldd r30,y+1
	ld r31,y
	ldi r22,5
	cli
	out spmcr,r22
	spm
	sei
	ldi r30,1
wrend:
#endasm
}
// 0--wait 1--finish
unsigned char read_enable(unsigned char a,unsigned char b)
{
#asm
	in r22,spmcr
	ldi r30,0
	sbrc r22,0
	rjmp rdend
	ldd r30,y+1
	ld r31,y
	ldi r22,0x11
	cli
	out spmcr,r22
	spm
	sei
	ldi r30,1
rdend:
#endasm
}
unsigned char i_write;
void write_flash(void)
{
	unsigned char a,b,c,d,i,j;
	a=rt_buffer[1]&0x7f;
	b=a>>2;
	a<<=6;
	switch (step)
	{
		case 1:
			j=erase_doing(a,b);
			i_write=0;
			if (j>0)
				step++;
			break;
		case 2:
			c=rt_buffer[i_write+4];
			d=rt_buffer[i_write+5];
			j=write_flashbuf(a+i_write,b,c,d);
			if (j>0)
			{
				i_write+=2;
				if (i_write>=64)
				{
					step++;
				}
			}
			break;
		case 3:
			j=write_doing(a,b);
			if (j>0)
			{
				step++;
			}
			break;
		case 4:
			j=read_enable(a,b);
			if (j>0)
			{
				step++;
			}
			break;
		case 5:
			write_timeover=0;
			b_tx_sign=1;
			break;
	}
}