Mega1280的BootLoader故障 - - Powered by Discuz!

/*****************************************************
采用串行接口实现Boot_load应用的实例华东师大电子系马潮
Compiler: ICC-AVR 7.22
Target: Mega128 改 Mega1280
Crystal: 16Mhz
Used: T/C0,USART0
2024-5-13改部转义字符 '/' 为 '\' 和部分错误
2024-5-18修改为Mega1280能通信刷机，但刷完运行不正常
*****************************************************/
#include <iom1280v.h>
#define SPM_PAGESIZE 256 //M128的一个Flash页为256字节(128字)
#define BAUD 19200 //波特率采用38400bps
#define CRYSTAL 16000000 //系统时钟16MHz
//计算和定义M128的波特率设置参数
#define BAUD_SETTING (unsigned char)((unsigned long)CRYSTAL/(16*(unsigned long)BAUD)-1)
#define BAUD_H (unsigned char)(BAUD_SETTING>>8)
#define BAUD_L (unsigned char)(BAUD_SETTING)
#define DATA_BUFFER_SIZE SPM_PAGESIZE //定义接收缓冲区长度
//定义Xmoden控制字符
#define XMODEM_NUL 0x00
#define XMODEM_SOH 0x01
#define XMODEM_STX 0x02
#define XMODEM_EOT 0x04
#define XMODEM_ACK 0x06
#define XMODEM_NAK 0x15
#define XMODEM_CAN 0x18
#define XMODEM_EOF 0x1A
#define XMODEM_RECIEVING_WAIT_CHAR 'C'
//定义全局变量
char data[DATA_BUFFER_SIZE];
long address = 0;
//擦除(code=0x03)和写入(code=0x05)一个Flash页
void boot_page_ew(long p_address, char code)
{
asm("mov r30,r16\n"
"mov r31,r17\n"
"out 0x3b,r18\n"); //将页地址放入Z寄存器和RAMPZ的Bit0中
SPMCSR = code; //寄存器SPMCSR中为操作码
asm("spm\n"); //对指定Flash页进行操作
}
//填充Flash缓冲页中的一个字
void boot_page_fill(unsigned int address, int data)
{
asm("mov r30,r16\n"
"mov r31,r17\n" //Z寄存器中为填冲页内地址
"mov r0,r18\n"
"mov r1,r19\n"); //r0R1中为一个指令字
SPMCSR = 0x01;
asm("spm\n");
}
//等待一个Flash页的写完成
void wait_page_rw_ok(void)
{
while(SPMCSR & 0x40)
{
while(SPMCSR & 0x01);
SPMCSR = 0x11;
asm("spm\n");
}
}
//更新一个Flash页的完整处理
void write_one_page(void)
{
int i;
boot_page_ew(address, 0x03); //擦除一个Flash页
wait_page_rw_ok(); //等待擦除完成
for(i = 0; i < SPM_PAGESIZE; i += 2) //将数据填入Flash缓冲页中
{
boot_page_fill(i, data[i] + (data[i + 1] << 8));
}
boot_page_ew(address, 0x05); //将缓冲页数据写入一个Flash页
wait_page_rw_ok(); //等待写入完成
}
//从RS232发送一个字节
void uart_putchar(char c)
{
while(!(UCSR0A & 0x20));
UDR0 = c;
}
//从RS232接收一个字节
int uart_getchar(void)
{
unsigned char status, res;
if(!(UCSR0A & 0x80)) return -1; //no data to be received
status = UCSR0A;
res = UDR0;
if (status & 0x1c) return -1; // If error, return -1
return res;
}
//等待从RS232接收一个有效的字节
char uart_waitchar(void)
{
int c;
while((c = uart_getchar()) == -1);
return (char)c;
}
//计算CRC
int calcrc(char *ptr, int count)
{
int crc = 0;
char i;
while (--count >= 0)
{
crc = crc ^ (int) * ptr++ << 8;
i = 8;
do
{
if (crc & 0x8000)
crc = crc << 1 ^ 0x1021;
else
crc = crc << 1;
}
while(--i);
}
return (crc);
}
//退出Bootloader程序，从0x0000处执行应用程序
void quit(void)
{
//uart_putchar('O');
//uart_putchar('K');
//while(!(UCSR0A & 0x20)); //等待结束提示信息回送完成
MCUCR = 0x01;
MCUCR = 0x00; //将中断向量表迁移到应用程序区头部
RAMPZ = 0x00; //rAMPZ清零初始化
asm("jmp 0x0000\n"); //跳转到Flash的0x0000处，执行用户的应用程序
}
//UART0 initialize
// desired baud rate: 19200
// actual: baud rate:19231 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
UCSR0B = 0x00; //disable while setting baud rate
UCSR0A = 0x00;
UCSR0C = 0x06;
UBRR0H = BAUD_H;
UBRR0L = BAUD_L; //Set baud rate
UCSR0B = 0x18;
}
//TIMER0 initialize - prescale:1024
// desired value: 15mSec
// actual value: 14.976mSec (0.2%)
void timer0_init(void)
{
TCCR0B = 0x00; //stop
TCNT0 = 0x16; //set count
OCR0A = 0xEA;
TCCR0A = 0x00; //start timer
TCCR0B = 0x05; //start timer
}
//主程序
void main(void)
{
int i = 0;
unsigned char timercount = 0;
unsigned char packNO = 1;
int bufferPoint = 0;
unsigned int crc;
uart0_init();
timer0_init();
//3秒种等待PC下发"d"，否则退出Bootloader程序，从0x0000处执行应用程序
while(1)
{
if(uart_getchar() == 'd')
{
uart_putchar(XMODEM_RECIEVING_WAIT_CHAR);
break;
}
if (TIFR0 & 0x02) //timer0 over flow
{
if (++timercount > 200)
quit(); //200*15ms = 3s
TIFR0 = TIFR0 | 0x02;
}
}
//每秒向PC机发送一个控制字符"C"，等待控制字〈soh?
while(uart_getchar() != XMODEM_SOH) //receive the start of Xmodem
{
if(TIFR0 & 0x02) //timer0 over flow
{
if(++timercount > 80) //wait about 1 second
{
uart_putchar(XMODEM_RECIEVING_WAIT_CHAR); //send a "C"
timercount = 0;
}
TIFR0 = TIFR0 | 0x02;
}
}
//开始接收数据块
do
{
if ((packNO == uart_waitchar()) && (packNO == (~uart_waitchar())))
{
//核对数据块编号正确
for(i = 0; i < 128; i++) //接收128个字节数据
{
data[bufferPoint] = uart_waitchar();
bufferPoint++;
}
crc = (uart_waitchar() << 8);
crc += uart_waitchar(); //接收2个字节的CRC效验字
if(calcrc(&data[bufferPoint - 128], 128) == crc) //CRC校验验证
{
//正确接收128个字节数据
while(bufferPoint >= SPM_PAGESIZE)
{
//正确接受256个字节的数据
write_one_page(); //收到256字节写入一页Flash中
address += SPM_PAGESIZE; //Flash页加1
bufferPoint = 0;
}
uart_putchar(XMODEM_ACK); //正确收到一个数据块
packNO++; //数据块编号加1
}
else
{
uart_putchar(XMODEM_NAK); //要求重发数据块
}
}
else
{
uart_putchar(XMODEM_NAK); //要求重发数据块
}
}
while(uart_waitchar() != XMODEM_EOT); //循环接收，直到全部发完
uart_putchar(XMODEM_ACK); //通知PC机全部收到
if(bufferPoint) write_one_page(); //把剩余的数据写入Flash中
quit(); //退出Bootloader程序，从0x0000处执行应用程序
}

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