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<html> <head> <title>CMSIS Changes</title> <meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> <meta name="GENERATOR" content="Microsoft FrontPage 6.0"> <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>Changes to CMSIS version V1.20</h1> <hr> <h2>1. Removed CMSIS Middelware packages</h2> <p> CMSIS Middleware is on hold from ARM side until a agreement between all CMSIS partners is found. </p> <h2>2. SystemFrequency renamed to SystemCoreClock</h2> <p> The variable name <strong>SystemCoreClock</strong> is more precise than <strong>SystemFrequency</strong> because the variable holds the clock value at which the core is running. </p> <h2>3. Changed startup concept</h2> <p> The old startup concept (calling SystemInit_ExtMemCtl from startup file and calling SystemInit from main) has the weakness that it does not work for controllers which need a already configuerd clock system to configure the external memory controller. </p> <h3>Changed startup concept</h3> <ul> <li> SystemInit() is called from startup file before <strong>premain</strong>. </li> <li> <strong>SystemInit()</strong> configures the clock system and also configures an existing external memory controller. </li> <li> <strong>SystemInit()</strong> must not use global variables. </li> <li> <strong>SystemCoreClock</strong> is initialized with a correct predefined value. </li> <li> Additional function <strong>void SystemCoreClockUpdate (void)</strong> is provided.<br> <strong>SystemCoreClockUpdate()</strong> updates the variable <strong>SystemCoreClock</strong> and must be called whenever the core clock is changed.<br> <strong>SystemCoreClockUpdate()</strong> evaluates the clock register settings and calculates the current core clock. </li> </ul> <h2>4. Advanced Debug Functions</h2> <p> ITM communication channel is only capable for OUT direction. To allow also communication for IN direction a simple concept is provided. </p> <ul> <li> Global variable <strong>volatile int ITM_RxBuffer</strong> used for IN data. </li> <li> Function <strong>int ITM_CheckChar (void)</strong> checks if a new character is available. </li> <li> Function <strong>int ITM_ReceiveChar (void)</strong> retrieves the new character. </li> </ul> <p> For detailed explanation see file <strong>CMSIS debug support.htm</strong>. </p> <h2>5. Core Register Bit Definitions</h2> <p> Files core_cm3.h and core_cm0.h contain now bit definitions for Core Registers. The name for the defines correspond with the Cortex-M Technical Reference Manual. </p> <p> e.g. SysTick structure with bit definitions </p> <pre> /** @addtogroup CMSIS_CM3_SysTick CMSIS CM3 SysTick memory mapped structure for SysTick @{ */ typedef struct { __IO uint32_t CTRL; /*!< Offset: 0x00 SysTick Control and Status Register */ __IO uint32_t LOAD; /*!< Offset: 0x04 SysTick Reload Value Register */ __IO uint32_t VAL; /*!< Offset: 0x08 SysTick Current Value Register */ __I uint32_t CALIB; /*!< Offset: 0x0C SysTick Calibration Register */ } SysTick_Type; /* SysTick Control / Status Register Definitions */ #define SysTick_CTRL_COUNTFLAG_Pos 16 /*!< SysTick CTRL: COUNTFLAG Position */ #define SysTick_CTRL_COUNTFLAG_Msk (1ul << SysTick_CTRL_COUNTFLAG_Pos) /*!< SysTick CTRL: COUNTFLAG Mask */ #define SysTick_CTRL_CLKSOURCE_Pos 2 /*!< SysTick CTRL: CLKSOURCE Position */ #define SysTick_CTRL_CLKSOURCE_Msk (1ul << SysTick_CTRL_CLKSOURCE_Pos) /*!< SysTick CTRL: CLKSOURCE Mask */ #define SysTick_CTRL_TICKINT_Pos 1 /*!< SysTick CTRL: TICKINT Position */ #define SysTick_CTRL_TICKINT_Msk (1ul << SysTick_CTRL_TICKINT_Pos) /*!< SysTick CTRL: TICKINT Mask */ #define SysTick_CTRL_ENABLE_Pos 0 /*!< SysTick CTRL: ENABLE Position */ #define SysTick_CTRL_ENABLE_Msk (1ul << SysTick_CTRL_ENABLE_Pos) /*!< SysTick CTRL: ENABLE Mask */ /* SysTick Reload Register Definitions */ #define SysTick_LOAD_RELOAD_Pos 0 /*!< SysTick LOAD: RELOAD Position */ #define SysTick_LOAD_RELOAD_Msk (0xFFFFFFul << SysTick_LOAD_RELOAD_Pos) /*!< SysTick LOAD: RELOAD Mask */ /* SysTick Current Register Definitions */ #define SysTick_VAL_CURRENT_Pos 0 /*!< SysTick VAL: CURRENT Position */ #define SysTick_VAL_CURRENT_Msk (0xFFFFFFul << SysTick_VAL_CURRENT_Pos) /*!< SysTick VAL: CURRENT Mask */ /* SysTick Calibration Register Definitions */ #define SysTick_CALIB_NOREF_Pos 31 /*!< SysTick CALIB: NOREF Position */ #define SysTick_CALIB_NOREF_Msk (1ul << SysTick_CALIB_NOREF_Pos) /*!< SysTick CALIB: NOREF Mask */ #define SysTick_CALIB_SKEW_Pos 30 /*!< SysTick CALIB: SKEW Position */ #define SysTick_CALIB_SKEW_Msk (1ul << SysTick_CALIB_SKEW_Pos) /*!< SysTick CALIB: SKEW Mask */ #define SysTick_CALIB_TENMS_Pos 0 /*!< SysTick CALIB: TENMS Position */ #define SysTick_CALIB_TENMS_Msk (0xFFFFFFul << SysTick_VAL_CURRENT_Pos) /*!< SysTick CALIB: TENMS Mask */ /*@}*/ /* end of group CMSIS_CM3_SysTick */</pre> <h2>7. DoxyGen Tags</h2> <p> DoxyGen tags in files core_cm3.[c,h] and core_cm0.[c,h] are reworked to create proper documentation using DoxyGen. </p> <h2>8. Folder Structure</h2> <p> The folder structure is changed to differentiate the single support packages. </p> <ul> <li>CM0</li> <li>CM3 <ul> <li>CoreSupport</li> <li>DeviceSupport</li> <ul> <li>Vendor <ul> <li>Device <ul> <li>Startup <ul> <li>Toolchain</li> <li>Toolchain</li> <li>...</li> </ul> </li> </ul> </li> <li>Device</li> <li>...</li> </ul> </li> <li>Vendor</li> <li>...</li> </ul> </li> <li>Example <ul> <li>Toolchain <ul> <li>Device</li> <li>Device</li> <li>...</li> </ul> </li> <li>Toolchain</li> <li>...</li> </ul> </li> </ul> </li> <li>Documentation</li> </ul> <h2>9. Open Points</h2> <p> Following points need to be clarified and solved: </p> <ul> <li> <p> Equivalent C and Assembler startup files. </p> <p> Is there a need for having C startup files although assembler startup files are very efficient and do not need to be changed? <p/> </li> <li> <p> Placing of HEAP in external RAM. </p> <p> It must be possible to place HEAP in external RAM if the device supports an external memory controller. </p> </li> <li> <p> Placing of STACK /HEAP. </p> <p> STACK should always be placed at the end of internal RAM. </p> <p> If HEAP is placed in internal RAM than it should be placed after RW ZI section. </p> </li> <li> <p> Removing core_cm3.c and core_cm0.c. </p> <p> On a long term the functions in core_cm3.c and core_cm0.c must be replaced with appropriate compiler intrinsics. </p> </li> </ul> <h2>10. Limitations</h2> <p> The following limitations are not covered with the current CMSIS version: </p> <ul> <li> No <strong>C startup files</strong> for ARM toolchain are provided. </li> <li> No <strong>C startup files</strong> for GNU toolchain are provided. </li> <li> No <strong>C startup files</strong> for IAR toolchain are provided. </li> <li> No <strong>Tasking</strong> projects are provided yet. </li> </ul>
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