关于M480_BSP_CMSIS中的HSUSBD Transfer例

2万 · 2021-4-8 14:30

在Readpages回buf验证处，有些怪怪的(....StdDriver\HSUSBD_HID_Transfer\WindowsTool....)
想知道为何这样比对
for(i=0;i<TEST_PAGES*PAGE_SIZE;i++)
      buf = i&0xFF;
WritePages(buf, TEST_BASE / PAGE_SIZE, TEST_PAGES);
memset(buf, 0xCC, TEST_PAGES*PAGE_SIZE);

ReadPages(buf, TEST_BASE / PAGE_SIZE, TEST_PAGES);
isErr = 0;
for(i=0;i<TEST_PAGES*PAGE_SIZE;i++)
{
      if(buf != 0xFF)
      {
         isErr = 1;
         break;
      }
}
buf(in)处的比对是与0xFF进行比对
几乎同样的例子，在Nano120的范例(....StdDriver\USBD_HID_Transfer\WindowsTool....)是
for(i = 0; i < TEST_PAGES * PAGE_SIZE; i++)
      buf = i & 0xFF;
WritePages(buf, TEST_BASE / PAGE_SIZE, TEST_PAGES);
memset(buf, 0xCC, TEST_PAGES * PAGE_SIZE);
ReadPages(buf, TEST_BASE / PAGE_SIZE, TEST_PAGES);
isErr = 0;
for(i = 0; i < TEST_PAGES * PAGE_SIZE; i++)
{
      if(buf != (i & 0xFF))
      {
         isErr = 1;
         break;
      }
}

1万 · 2021-4-8 14:35

是根据MCU例程代码里IN 令牌后发，MCU发送出去的数据决定的
if(g_u32BytesInPageBuf == 0)
         {
            /* The previous page has sent out. Read new page to page buffer */
            /* TODO: We should update new page data here. (0xFF is used in this sample code) */
            printf("Reading page %d\n", u32StartPage + u32PageCnt);
            for(i=0; i<PAGE_SIZE; i++)
                  g_u8PageBuff = 0xFF;

            g_u32BytesInPageBuf = PAGE_SIZE;

            /* Update the page counter */
            u32PageCnt++;
         }

         /* Prepare the data for next HID IN transfer */
         len = Minimum(g_u32EpAMaxPacketSize, g_u32BytesInPageBuf);
         for (i=0; i<len; i++)
            HSUSBD->EP[EPA].EPDAT_BYTE = g_u8PageBuff[PAGE_SIZE - g_u32BytesInPageBuf];
         HSUSBD->EP[EPA].EPTXCNT = len;
         HSUSBD_ENABLE_EP_INT(EPA, HSUSBD_EPINTEN_INTKIEN_Msk);
         g_u32BytesInPageBuf -= len;

      }

只看该作者 · 2021-4-14 15:04

赞同楼上的