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[nRF51822] 11、基础实验代码解析大全 · 实验16 - 内部FLASH读写

一、实验内容：

　　通过串口发送单个字符到NRF51822，NRF51822 接收到字符后将其写入到FLASH 的最后一页，之后将其读出并通过串口打印出数据。

二、nRF51822芯片内部flash知识：

　　EN-nRF51D 开发板使用NRF51822 芯片为nRF51822-QFAA，如下图所示，共有256KBFLASH，256 页，页大小为1024 字节。

　　NRF51822 内部FLASH 写流程如下：

三、代码解析：

main:

 1 int main(void)
 2 {
 3     ...
 4     
 5     串口初始化
 6     
 7     printf("Flashwrite example\r\n");
 8     patold  = 0;
 9     pg_size = NRF_FICR->CODEPAGESIZE;
10     pg_num  = NRF_FICR->CODESIZE - 1;  // Use last page in flash
11 
12     while (true)
13     {
14         // Start address:
15         addr = (uint32_t *)(pg_size * pg_num);//计算地址并擦除一页
16         // Erase page:
17         flash_page_erase(addr);
18         i = 0;
19 
20         do
21         {
22             printf("Enter char to write to flash\r\n");
23 
24             // Read char from uart, and write it to flash:
25             do
26             {
27                 err_code = app_uart_get(&patwr);
28             }
29             while(err_code == NRF_ERROR_NOT_FOUND);//从串口获得1byte数据
30 
31             if (patold != patwr)//将1byte写入flash
32             {
33                 patold = patwr;
34                 flash_word_write(++addr, (uint32_t)patwr);
35                 i += 4;
36                 printf("'%c' was write to flash\r\n", patwr);
37             }
38             // Read pattern from flash and send it back:
39             patrd = (uint8_t) * addr;
40             printf("'%c' was read from flash\r\n", patrd);
41         }
42         while (i < pg_size);
43     }
44 }