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外部扩展 RAM 访问方式

2019-07-15 21:57发布

站内问答 / 51单片机
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tica, Tahoma, Arial, sans-serif">请问以下两种方式读取外部扩展RAM，有什么差别呢？为什么在我的程序返回的结果很怪呢？
方式一：
      j = 0x0016;
      k = 0x16;
      pToV = &pV->bTsAddr;//0x4016
      for( i = 0x16; i < RAM_LENGTH; i++ )
      {
         *pToV=k;
         
         abSndBuffer [bWriteSndPtr++] = 0x5A; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)(i>>8); bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)i; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = 0x5A; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)k; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = 0x5A; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)*pToV; bSndCounter++;
         StartSerialCommunication();
         pToV++;
         j++;k++;
      }

串口接收如下结果：
5A 00 16 5A 16 5A 16
5A 00 17 5A 17 5A 17
5A 00 18 5A 18 5A 18
5A 00 19 5A 19 5A 19
5A 00 1A 5A 1A 5A 1A
5A 00 1B 5A 1B 5A 1B
5A 00 1C 5A 1C 5A 1C
5A 00 1D 5A 1D 5A 1D
5A 00 1E 5A 1E 5A 1E
5A 00 1F 5A 1F 5A 1F
5A 00 20 5A 20 5A 20
. . .

方式二：
      j = 0x0016;
      pToV = &pV->bTsAddr;
      for( i = 0x16; i < RAM_LENGTH; )
      {
         *pToV = (uint8_t)(j>>8);
         pToV++;
         *pToV = (uint8_t)j;
         pToV++;

         abSndBuffer [bWriteSndPtr++] = 0x5A; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)(i>>8); bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)i; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)(j>>8); bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)j; bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)(*(pToV-2)); bSndCounter++;
         abSndBuffer [bWriteSndPtr++] = (uint8_t)(*(pToV-1)); bSndCounter++;
         StartSerialCommunication();

         i+=2;
         j+=2;
      }

串口接收如下结果：
5A 00 16 00 16 16 17
5A 00 18 00 18 18 19
5A 00 1A 00 1A 1A 1B
5A 00 1C 00 1C 1C 1D
5A 00 1E 00 1E 1E 1F
5A 00 20 00 20 20 21
. . .

各位帮忙看看吧，实在找不出问题在哪里
友情提示: 此问题已得到解决，问题已经关闭,关闭后问题禁止继续编辑，回答。
2条回答
xieyanji01
2019-07-15 22:06
高手呢，请高手出马呀。急等

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