60 lines
2.1 KiB
HTML
60 lines
2.1 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
|
|
<html lang="en">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
|
<link rel="up" title="Petit FatFs" href="../00index_p.html">
|
|
<link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default">
|
|
<link rel="stylesheet" href="../css_p.css" type="text/css" media="screen" title="ELM Default">
|
|
<title>Petit FatFs - disk_readp</title>
|
|
</head>
|
|
|
|
<body>
|
|
|
|
<div class="para">
|
|
<h2>disk_readp</h2>
|
|
<p>The disk_readp function reads a partial sector of the device.</p>
|
|
<pre>
|
|
DRESULT disk_readp (
|
|
BYTE* <span class="arg">buff</span>, <span class="c">/* [OUT] Pointer to the read buffer */</span>
|
|
DWORD <span class="arg">sector</span>, <span class="c">/* [IN] Sector number */</span>
|
|
UINT <span class="arg">offset</span>, <span class="c">/* [IN] Byte offset in the sector to start to read */</span>
|
|
UINT <span class="arg">count</span> <span class="c">/* [IN] Number of bytes to read */</span>
|
|
);
|
|
</pre>
|
|
</div>
|
|
|
|
<div class="para">
|
|
<h4>Parameters</h4>
|
|
<dl class="par">
|
|
<dt>buff</dt>
|
|
<dd>Pointer to the read buffer to store the read data. If a NULL is given, read bytes will be forwarded to the outgoing stream instead of the memory.</dd>
|
|
<dt>sector</dt>
|
|
<dd>Specifies the sector number to be read in logical block address (LBA).</dd>
|
|
<dt>offset</dt>
|
|
<dd>Specifies the byte offset in the sector to start to read. The value can be 0 to 511.</dd>
|
|
<dt>count</dt>
|
|
<dd>Specifies number of bytes to read. The value can be 0 to 512 and <tt class="arg">offset</tt> + <tt class="arg">count</tt> must not exceed 512.</dd>
|
|
</dl>
|
|
</div>
|
|
|
|
|
|
<div class="para">
|
|
<h4>Return Value</h4>
|
|
<dl class="ret">
|
|
<dt>RES_OK (0)</dt>
|
|
<dd>The function succeeded.</dd>
|
|
<dt>RES_ERROR</dt>
|
|
<dd>Any hard error occured during the disk read operation and could not recover it.</dd>
|
|
<dt>RES_PARERR</dt>
|
|
<dd>Invalid parameter.</dd>
|
|
<dt>RES_NOTRDY</dt>
|
|
<dd>The device has not been initialized.</dd>
|
|
</dl>
|
|
</div>
|
|
|
|
|
|
<p class="foot"><a href="../00index_p.html">Return</a></p>
|
|
</body>
|
|
</html>
|