mirror of
https://github.com/arduino/Arduino.git
synced 2024-12-11 22:24:13 +01:00
240 lines
9.5 KiB
HTML
240 lines
9.5 KiB
HTML
|
<html>
|
|||
|
|
|
|||
|
|
<head>
|
|||
|
|
<title>CMSIS Debug Support</title>
|
|||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
|
|||
|
|
<meta name="GENERATOR" content="Microsoft FrontPage 12.0">
|
|||
|
|
<meta name="ProgId" content="FrontPage.Editor.Document">
|
|||
|
|
<style>
|
|||
|
|
<!--
|
|||
|
|
/*-----------------------------------------------------------
|
|||
|
|
Keil Software CHM Style Sheet
|
|||
|
|
-----------------------------------------------------------*/
|
|||
|
|
body { color: #000000; background-color: #FFFFFF; font-size: 75%; font-family:
|
|||
|
|
Verdana, Arial, 'Sans Serif' }
|
|||
|
|
a:link { color: #0000FF; text-decoration: underline }
|
|||
|
|
a:visited { color: #0000FF; text-decoration: underline }
|
|||
|
|
a:active { color: #FF0000; text-decoration: underline }
|
|||
|
|
a:hover { color: #FF0000; text-decoration: underline }
|
|||
|
|
h1 { font-family: Verdana; font-size: 18pt; color: #000080; font-weight: bold;
|
|||
|
|
text-align: Center; margin-right: 3 }
|
|||
|
|
h2 { font-family: Verdana; font-size: 14pt; color: #000080; font-weight: bold;
|
|||
|
|
background-color: #CCCCCC; margin-top: 24; margin-bottom: 3;
|
|||
|
|
padding: 6 }
|
|||
|
|
h3 { font-family: Verdana; font-size: 10pt; font-weight: bold; background-color:
|
|||
|
|
#CCCCCC; margin-top: 24; margin-bottom: 3; padding: 6 }
|
|||
|
|
pre { font-family: Courier New; font-size: 10pt; background-color: #CCFFCC;
|
|||
|
|
margin-left: 24; margin-right: 24 }
|
|||
|
|
ul { list-style-type: square; margin-top: 6pt; margin-bottom: 0 }
|
|||
|
|
ol { margin-top: 6pt; margin-bottom: 0 }
|
|||
|
|
li { clear: both; margin-bottom: 6pt }
|
|||
|
|
table { font-size: 100%; border-width: 0; padding: 0 }
|
|||
|
|
th { color: #FFFFFF; background-color: #000080; text-align: left; vertical-align:
|
|||
|
|
bottom; padding-right: 6pt }
|
|||
|
|
tr { text-align: left; vertical-align: top }
|
|||
|
|
td { text-align: left; vertical-align: top; padding-right: 6pt }
|
|||
|
|
.ToolT { font-size: 8pt; color: #808080 }
|
|||
|
|
.TinyT { font-size: 8pt; text-align: Center }
|
|||
|
|
code { color: #000000; background-color: #E0E0E0; font-family: 'Courier New', Courier;
|
|||
|
|
line-height: 120%; font-style: normal }
|
|||
|
|
/*-----------------------------------------------------------
|
|||
|
|
Notes
|
|||
|
|
-----------------------------------------------------------*/
|
|||
|
|
p.note { font-weight: bold; clear: both; margin-bottom: 3pt; padding-top: 6pt }
|
|||
|
|
/*-----------------------------------------------------------
|
|||
|
|
Expanding/Contracting Divisions
|
|||
|
|
-----------------------------------------------------------*/
|
|||
|
|
#expand { text-decoration: none; margin-bottom: 3pt }
|
|||
|
|
img.expand { border-style: none; border-width: medium }
|
|||
|
|
div.expand { display: none; margin-left: 9pt; margin-top: 0 }
|
|||
|
|
/*-----------------------------------------------------------
|
|||
|
|
Where List Tags
|
|||
|
|
-----------------------------------------------------------*/
|
|||
|
|
p.wh { font-weight: bold; clear: both; margin-top: 6pt; margin-bottom: 3pt }
|
|||
|
|
table.wh { width: 100% }
|
|||
|
|
td.whItem { white-space: nowrap; font-style: italic; padding-right: 6pt; padding-bottom:
|
|||
|
|
6pt }
|
|||
|
|
td.whDesc { padding-bottom: 6pt }
|
|||
|
|
/*-----------------------------------------------------------
|
|||
|
|
Keil Table Tags
|
|||
|
|
-----------------------------------------------------------*/
|
|||
|
|
table.kt { border: 1pt solid #000000 }
|
|||
|
|
th.kt { white-space: nowrap; border-bottom: 1pt solid #000000; padding-left: 6pt;
|
|||
|
|
padding-right: 6pt; padding-top: 4pt; padding-bottom: 4pt }
|
|||
|
|
tr.kt { }
|
|||
|
|
td.kt { color: #000000; background-color: #E0E0E0; border-top: 1pt solid #A0A0A0;
|
|||
|
|
padding-left: 6pt; padding-right: 6pt; padding-top: 2pt;
|
|||
|
|
padding-bottom: 2pt }
|
|||
|
|
/*-----------------------------------------------------------
|
|||
|
|
-----------------------------------------------------------*/
|
|||
|
|
-->
|
|||
|
|
|
|||
|
|
</style>
|
|||
|
|
</head>
|
|||
|
|
|
|||
|
|
<body>
|
|||
|
|
|
|||
|
|
<h1>CMSIS Debug Support</h1>
|
|||
|
|
<p align="center">This file describes the CMSIS Debug support available with CMSIS (starting V1.30).</p>
|
|||
|
|
<p align="center">Version: 1.02 - 25. July 2011</p>
|
|||
|
|
|
|||
|
|
<p class="TinyT">Information in this file, the accompany manuals, and software is<br>
|
|||
|
|
Copyright <20> ARM Ltd.<br>All rights reserved.
|
|||
|
|
</p>
|
|||
|
|
|
|||
|
|
<hr>
|
|||
|
|
|
|||
|
|
<p><span style="FONT-WEIGHT: bold">Revision History</span></p>
|
|||
|
|
<ul>
|
|||
|
|
<li>Version 1.00: Initial Release. </li>
|
|||
|
|
<li>Version 1.01: Internal Review. </li>
|
|||
|
|
<li>Version 1.02: Removed product specific information. </li>
|
|||
|
|
</ul>
|
|||
|
|
|
|||
|
|
<hr>
|
|||
|
|
|
|||
|
|
<h2>Contents</h2>
|
|||
|
|
|
|||
|
|
<ol>
|
|||
|
|
<li class="LI2"><a href="#About">About</a></li>
|
|||
|
|
<li class="LI2"><a href="#ITM_DbgAcc">Cortex-M3 / Cortex-M4 ITM Debug Access</a></li>
|
|||
|
|
<li class="LI2"><a href="#DbgIn_DbgOut">Debug IN / OUT functions</a></li>
|
|||
|
|
<li class="LI2"><a href="#ITM_DbgSup">ITM Debug Support in Debugger</a></li>
|
|||
|
|
</ol>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
<h2><a name="About"></a>About</h2>
|
|||
|
|
<p>
|
|||
|
|
CMSIS provides for Cortex-M3 / Cortex-M4 processor based microcontrollers debug support via the Instrumented Trace Macrocell (ITM).
|
|||
|
|
This document describes the available CMSIS Debug functions and the used methods.
|
|||
|
|
</p>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
<h2><a name="ITM_DbgAcc"></a>Cortex-M3 / Cortex-M4 ITM Debug Access</h2>
|
|||
|
|
<p>
|
|||
|
|
The Cortex-M3 incorporates the Instrumented Trace Macrocell (ITM) that provides together with
|
|||
|
|
the Serial Viewer Output trace capabilities for the microcontroller system. The ITM has
|
|||
|
|
32 communication channels which are able to transmit 32 / 16 / 8 bit values; two ITM
|
|||
|
|
communication channels are used by CMSIS to output the following information:
|
|||
|
|
</p>
|
|||
|
|
<ul>
|
|||
|
|
<li>ITM Channel 0: used for printf-style output via the debug interface.</li>
|
|||
|
|
<li>ITM Channel 31: is reserved for RTOS kernel awareness debugging.</li>
|
|||
|
|
</ul>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
<h2><a name="DbgIn_DbgOut"></a>Debug IN / OUT functions</h2>
|
|||
|
|
<p>CMSIS provides following debug functions:</p>
|
|||
|
|
<ul>
|
|||
|
|
<li>ITM_SendChar (uses ITM channel 0)</li>
|
|||
|
|
<li>ITM_ReceiveChar (uses global variable)</li>
|
|||
|
|
<li>ITM_CheckChar (uses global variable)</li>
|
|||
|
|
</ul>
|
|||
|
|
|
|||
|
|
<h3>ITM_SendChar</h3>
|
|||
|
|
<p>
|
|||
|
|
<strong>ITM_SendChar</strong> is used to transmit a character over ITM channel 0 from
|
|||
|
|
the microcontroller system to the debug system. <br>
|
|||
|
|
Only a 8 bit value is transmitted.
|
|||
|
|
</p>
|
|||
|
|
<pre>
|
|||
|
|
static __INLINE uint32_t ITM_SendChar (uint32_t ch)
|
|||
|
|
{
|
|||
|
|
/* check if debugger connected and ITM channel enabled for tracing */
|
|||
|
|
if ((CoreDebug->DEMCR & CoreDebug_DEMCR_TRCENA) &&
|
|||
|
|
(ITM->TCR & ITM_TCR_ITMENA) &&
|
|||
|
|
(ITM->TER & (1UL << 0)) )
|
|||
|
|
{
|
|||
|
|
while (ITM->PORT[0].u32 == 0);
|
|||
|
|
ITM->PORT[0].u8 = (uint8_t)ch;
|
|||
|
|
}
|
|||
|
|
return (ch);
|
|||
|
|
}</pre>
|
|||
|
|
|
|||
|
|
<h3>ITM_ReceiveChar</h3>
|
|||
|
|
<p>
|
|||
|
|
ITM communication channel is only capable for OUT direction. For IN direction
|
|||
|
|
a global variable is used. A simple mechanism detects if a character is received.
|
|||
|
|
The project to test need to be build with debug information.
|
|||
|
|
</p>
|
|||
|
|
|
|||
|
|
<p>
|
|||
|
|
The global variable <strong>ITM_RxBuffer</strong> is used to transmit a 8 bit value from debug system
|
|||
|
|
to microcontroller system. <strong>ITM_RxBuffer</strong> is 32 bit wide to
|
|||
|
|
ensure a proper handshake.
|
|||
|
|
</p>
|
|||
|
|
<pre>
|
|||
|
|
extern volatile int32_t ITM_RxBuffer; /* variable to receive characters */
|
|||
|
|
</pre>
|
|||
|
|
<p>
|
|||
|
|
A dedicated bit pattern is used to determine if <strong>ITM_RxBuffer</strong> is empty
|
|||
|
|
or contains a valid value.
|
|||
|
|
</p>
|
|||
|
|
<pre>
|
|||
|
|
#define ITM_RXBUFFER_EMPTY 0x5AA55AA5 /* value identifying ITM_RxBuffer is ready for next character */
|
|||
|
|
</pre>
|
|||
|
|
<p>
|
|||
|
|
<strong>ITM_ReceiveChar</strong> is used to receive a 8 bit value from the debug system. The function is nonblocking.
|
|||
|
|
It returns the received character or '-1' if no character was available.
|
|||
|
|
</p>
|
|||
|
|
<pre>
|
|||
|
|
static __INLINE int32_t ITM_ReceiveChar (void) {
|
|||
|
|
int32_t ch = -1; /* no character available */
|
|||
|
|
|
|||
|
|
if (ITM_RxBuffer != ITM_RXBUFFER_EMPTY) {
|
|||
|
|
ch = ITM_RxBuffer;
|
|||
|
|
ITM_RxBuffer = ITM_RXBUFFER_EMPTY; /* ready for next character */
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return (ch);
|
|||
|
|
}
|
|||
|
|
</pre>
|
|||
|
|
|
|||
|
|
<h3>ITM_CheckChar</h3>
|
|||
|
|
<p>
|
|||
|
|
<strong>ITM_CheckChar</strong> is used to check if a character is received.
|
|||
|
|
</p>
|
|||
|
|
<pre>
|
|||
|
|
static __INLINE int32_t ITM_CheckChar (void) {
|
|||
|
|
|
|||
|
|
if (ITM_RxBuffer == ITM_RXBUFFER_EMPTY) {
|
|||
|
|
return (0); /* no character available */
|
|||
|
|
} else {
|
|||
|
|
return (1); /* character available */
|
|||
|
|
}
|
|||
|
|
}</pre>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
<h2><a name="ITM_DbgSup"></a>ITM Debug Support in a Debugger</h2>
|
|||
|
|
<p>
|
|||
|
|
The Debugger shall offer a dedicated console window for printf style debug input and output using the CMSIS defined ITM methods described above.
|
|||
|
|
</p>
|
|||
|
|
<p>Direction: Microcontroller -> Debugger:</p>
|
|||
|
|
<ul>
|
|||
|
|
<li>
|
|||
|
|
at the beginning of a debug session the debugger shall enable ITM trace on channel 0 and continuously snoop for channel 0 data on the ITM trace
|
|||
|
|
stream it receives from the Microcontroller's CoreSight ITM unit
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
data received via the ITM communication channel 0 is interpreted as charater and gets redirected into the dedicated <strong>Console Window</strong>
|
|||
|
|
</li>
|
|||
|
|
</ul>
|
|||
|
|
|
|||
|
|
<p>Direction: Debugger -> Microcontroller:</p>
|
|||
|
|
<ul>
|
|||
|
|
<li>
|
|||
|
|
at the beginning of a debug session the debugger shall seek for the presence of the global variable named <strong>ITM_RxBuffer</strong> in the debug
|
|||
|
|
information of the application being loaded
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
strings entered into the <strong>Console Window</strong> are written by the debugger as a stream of char values via the variable <strong>ITM_RxBuffer</strong>.
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
the debugger writes the next character into the <strong>ITM_RxBuffer</strong> only once the value has been read and the <strong>ITM_RXBUFFER_EMPTY</strong> value being set.
|
|||
|
|
(refer to: ITM_ReceiveChar()).
|
|||
|
|
</ul>
|
|||
|
|
|
|||
|
|
</body>
|
|||
|
|
|
|||
|
|
</html>
|