summaryrefslogtreecommitdiff
path: root/CMSIS/Documentation/Core/html/system_c_pg.html
blob: c2983501838bbcc7e5a18d1a216a52a231dcf741 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<title>System Configuration Files system_&lt;device&gt;.c and system_&lt;device&gt;.h</title>
<title>CMSIS-CORE: System Configuration Files system_&lt;device&gt;.c and system_&lt;device&gt;.h</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<link href="cmsis.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<script type="text/javascript" src="printComponentTabs.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<script type="text/javascript">
  $(document).ready(initResizable);
</script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
  $(document).ready(function() { searchBox.OnSelectItem(0); });
</script>
<link href="stylsheetf" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
 <tbody>
 <tr style="height: 46px;">
  <td id="projectlogo"><img alt="Logo" src="CMSIS_Logo_Final.png"/></td>
  <td style="padding-left: 0.5em;">
   <div id="projectname">CMSIS-CORE
   &#160;<span id="projectnumber">Version 4.30</span>
   </div>
   <div id="projectbrief">CMSIS-CORE support for Cortex-M processor-based devices</div>
  </td>
 </tr>
 </tbody>
</table>
</div>
<!-- end header part -->
<div id="CMSISnav" class="tabs1">
    <ul class="tablist">
      <script type="text/javascript">
		<!--
		writeComponentTabs.call(this);
		//-->
      </script>
	  </ul>
</div>
<!-- Generated by Doxygen 1.8.2 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
  <div id="navrow1" class="tabs">
    <ul class="tablist">
      <li><a href="index.html"><span>Main&#160;Page</span></a></li>
      <li class="current"><a href="pages.html"><span>Usage&#160;and&#160;Description</span></a></li>
      <li><a href="modules.html"><span>Reference</span></a></li>
      <li>
        <div id="MSearchBox" class="MSearchBoxInactive">
        <span class="left">
          <img id="MSearchSelect" src="search/mag_sel.png"
               onmouseover="return searchBox.OnSearchSelectShow()"
               onmouseout="return searchBox.OnSearchSelectHide()"
               alt=""/>
          <input type="text" id="MSearchField" value="Search" accesskey="S"
               onfocus="searchBox.OnSearchFieldFocus(true)" 
               onblur="searchBox.OnSearchFieldFocus(false)" 
               onkeyup="searchBox.OnSearchFieldChange(event)"/>
          </span><span class="right">
            <a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
          </span>
        </div>
      </li>
    </ul>
  </div>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
  <div id="nav-tree">
    <div id="nav-tree-contents">
      <div id="nav-sync" class="sync"></div>
    </div>
  </div>
  <div id="splitbar" style="-moz-user-select:none;" 
       class="ui-resizable-handle">
  </div>
</div>
<script type="text/javascript">
$(document).ready(function(){initNavTree('system_c_pg.html','');});
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
     onmouseover="return searchBox.OnSearchSelectShow()"
     onmouseout="return searchBox.OnSearchSelectHide()"
     onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark">&#160;</span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark">&#160;</span>Data Structures</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark">&#160;</span>Files</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark">&#160;</span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark">&#160;</span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark">&#160;</span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark">&#160;</span>Enumerator</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark">&#160;</span>Groups</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(8)"><span class="SelectionMark">&#160;</span>Pages</a></div>

<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0" 
        name="MSearchResults" id="MSearchResults">
</iframe>
</div>

<div class="header">
  <div class="headertitle">
<div class="title">System Configuration Files system_&lt;device&gt;.c and system_&lt;device&gt;.h </div>  </div>
</div><!--header-->
<div class="contents">
<div class="textblock"><p>The <a class="el" href="system_c_pg.html">System Configuration Files system_&lt;device&gt;.c and system_&lt;device&gt;.h</a> provides as a minimum the functions described under <a class="el" href="group__system__init__gr.html">System and Clock Configuration</a>. These functions are device specific and need adaptations. In addition, the file might have configuration settings for the device such as XTAL frequency or PLL prescaler settings.</p>
<p>For devices with external memory BUS the system_&lt;device&gt;.c also configures the BUS system.</p>
<p>The silicon vendor might expose other functions (i.e. for power configuration) in the system_&lt;device&gt;.c file. In case of additional features the function prototypes need to be added to the system_&lt;device&gt;.h header file.</p>
<h1><a class="anchor" id="system_Device_sec"></a>
system_Device.c Template File</h1>
<p>The <a class="el" href="system_c_pg.html#system_Device_sec">system_Device.c Template File</a> for the Cortex-M3 is shown below.</p>
<pre class="fragment">/**************************************************************************//**
 * @file     system_&lt;Device&gt;.c
 * @brief    CMSIS Cortex-M# Device Peripheral Access Layer Source File for
 *           Device &lt;Device&gt;
 * @version  V3.10
 * @date     23. November 2012
 *
 * @note
 *
 ******************************************************************************/
/* Copyright (c) 2012 ARM LIMITED

   All rights reserved.
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions are met:
   - Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
   - Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
   - Neither the name of ARM nor the names of its contributors may be used
     to endorse or promote products derived from this software without
     specific prior written permission.
   *
   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE.
   ---------------------------------------------------------------------------*/


#include &lt;stdint.h&gt;
#include "&lt;Device&gt;.h"


/*----------------------------------------------------------------------------
  DEFINES
 *----------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
  Define clocks
 *----------------------------------------------------------------------------*/
/* ToDo: add here your necessary defines for device initialization
         following is an example for different system frequencies             */
#define __HSI             ( 6000000UL)
#define __XTAL            (12000000UL)    /* Oscillator frequency             */
#define __SYS_OSC_CLK     (    ___HSI)    /* Main oscillator frequency        */

#define __SYSTEM_CLOCK    (4*__XTAL)


/*----------------------------------------------------------------------------
  Clock Variable definitions
 *----------------------------------------------------------------------------*/
/* ToDo: initialize SystemCoreClock with the system core clock frequency value
         achieved after system intitialization.
         This means system core clock frequency after call to SystemInit()    */
uint32_t SystemCoreClock = __SYSTEM_CLOCK;  /*!&lt; System Clock Frequency (Core Clock)*/


/*----------------------------------------------------------------------------
  Clock functions
 *----------------------------------------------------------------------------*/
void SystemCoreClockUpdate (void)            /* Get Core Clock Frequency      */
{
/* ToDo: add code to calculate the system frequency based upon the current
         register settings.
         This function can be used to retrieve the system core clock frequeny
         after user changed register sittings.                                */
  SystemCoreClock = __SYSTEM_CLOCK;
}

/**
 * Initialize the system
 *
 * @param  none
 * @return none
 *
 * @brief  Setup the microcontroller system.
 *         Initialize the System.
 */
void SystemInit (void)
{
/* ToDo: add code to initialize the system
         do not use global variables because this function is called before
         reaching pre-main. RW section maybe overwritten afterwards.          */
  SystemCoreClock = __SYSTEM_CLOCK;
}
</pre><h1><a class="anchor" id="system_Device_h_sec"></a>
system_Device.h Template File</h1>
<p>The system_&lt;device&gt;.h header file contains prototypes to access the public functions in the system_&lt;device&gt;.c file. The <a class="el" href="system_c_pg.html#system_Device_h_sec">system_Device.h Template File</a> is shown below.</p>
<pre class="fragment">/**************************************************************************//**
 * @file     system_&lt;Device&gt;.h
 * @brief    CMSIS Cortex-M# Device Peripheral Access Layer Header File for
 *           Device &lt;Device&gt;
 * @version  V3.10
 * @date     23. November 2012
 *
 * @note
 *
 ******************************************************************************/
/* Copyright (c) 2012 ARM LIMITED

   All rights reserved.
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions are met:
   - Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
   - Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
   - Neither the name of ARM nor the names of its contributors may be used
     to endorse or promote products derived from this software without
     specific prior written permission.
   *
   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE.
   ---------------------------------------------------------------------------*/


#ifndef SYSTEM_&lt;Device&gt;_H   /* ToDo: replace '&lt;Device&gt;' with your device name */
#define SYSTEM_&lt;Device&gt;_H

#ifdef __cplusplus
extern "C" {
#endif

#include &lt;stdint.h&gt;

extern uint32_t SystemCoreClock;     /*!&lt; System Clock Frequency (Core Clock)  */


/**
 * Initialize the system
 *
 * @param  none
 * @return none
 *
 * @brief  Setup the microcontroller system.
 *         Initialize the System and update the SystemCoreClock variable.
 */
extern void SystemInit (void);

/**
 * Update SystemCoreClock variable
 *
 * @param  none
 * @return none
 *
 * @brief  Updates the SystemCoreClock with current core Clock
 *         retrieved from cpu registers.
 */
extern void SystemCoreClockUpdate (void);

#ifdef __cplusplus
}
#endif

#endif /* SYSTEM_&lt;Device&gt;_H */
</pre> </div></div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
  <ul>
    <li class="navelem"><a class="el" href="_templates_pg.html">Template Files</a></li>
    <li class="footer">Generated on Tue Oct 27 2015 14:35:21 for CMSIS-CORE by ARM Ltd. All rights reserved.
	<!--
    <a href="http://www.doxygen.org/index.html">
    <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.2 
	-->
	</li>
  </ul>
</div>
</body>
</html>