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FatFs R0.11a, released September 5, 2015

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This commit is contained in:
Christopher Williams
2015-10-19 08:53:27 -07:00
parent 095cc0fc01
commit 95374bbf12
81 changed files with 5038 additions and 4673 deletions
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doc/en/dread.html
+3 -3
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@@ -34,7 +34,7 @@ DRESULT disk_read (
<dt>sector</dt>
<dd>Start sector number in 32-bit LBA.</dd>
<dt>count</dt>
<dd>Number of sectors to read in range of from 1 to 128..</dd>
<dd>Number of sectors to read. FatFs specifies the value in range of from 1 to 128.</dd>
</dl>
</div>
@@ -60,8 +60,8 @@ DRESULT disk_read (
<p>The memory address specified by <tt class="arg">buff</tt> is not that always aligned to word boundary because the argument is defined as <tt>BYTE*</tt>. The misaligned read/write request can occure at <a href="appnote.html#fs1">direct transfer</a>. If the bus architecture, especially DMA controller, does not allow misaligned memory access, it should be solved in this function. There are some workarounds described below to avoid this issue.</p>
<ul>
<li>Convert word transfer to byte transfer in this function if needed. - Recommended.</li>
<li>For any <tt>f_read</tt> calls, avoid long read request that includes a whole of sector. - Direct transfer will never occure.</li>
<li>For <tt>f_read(fp, buff, btr, &amp;br)</tt> call, make sure that <tt>(((UINT)buff &amp; 3) == (f_tell(fp) &amp; 3))</tt> is true. - Word aligned direct transfer is guaranteed.</li>
<li>At the any <tt>f_read</tt> calls, avoid long read request that includes a whole of sector. - Direct transfer will never occure.</li>
<li>At the <tt>f_read(fp, data, btr, &amp;br)</tt> call, make sure that <tt>(((UINT)data &amp; 3) == (f_tell(fp) &amp; 3))</tt> is true. - Word alignment of <tt>buff</tt> is guaranteed.</li>
</ul>
<p>Generally, a multiple sector transfer request must not be split into single sector transactions to the storage device, or you will not get good read throughput.</p>
</div>