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75 lines
2.8 KiB
Plaintext
75 lines
2.8 KiB
Plaintext
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About this Example
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==================
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This example demonstrates how to use the uVision IDE together with
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the MDK-ARM toolchain.
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***
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NOTE: This example requires installing the following Software Pack
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in the Keil uVision: Keil::STM32L152_DFP.
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***
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uVision Project File
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====================
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The MDK-ARM uVision project file provided with this example uses
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relative paths to the QP/C framework location (includes, port, and
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libraries. These relative paths must be modified when the project
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is moved to different relative location.
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Adjusting Stack and Heap Sizes
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==============================
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The stack and heap sizes are determined in this project by the
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command-line options for the ARM assembler (see the Asm tab in
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the "Options for Target" dialog box in uVision). Specifically,
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you should define symbols: Stack_Size=xxx Heap_Size=yyy, where
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xxx represents a numerical value of stack size and yyy the
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numberical value of the heap size (for most embedded projects
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yyy should be 0, as the using the heap is not recommended).
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Startup Code
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============
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The startup code for the STM32L1xx MCU used in this project is
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located in the "3rd_party" folder in the following location:
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3rd_party\nucleo-l152re\arm\startup_stm32l1xx.s
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The file startup_stm32l1xx.s provides a template of the recommended
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startup for QP applications and should be easily customizable for other
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ARM Cortex-M microcontrollers.
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The startup file typically does not need to be modified or adapted for
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applications. It provides only weak definitions of all exception and
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interrupt handlers, as well as the assert_failed() function.
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The weak function assert_failed() defined in this file might be re-defined
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in the application to customize it for the application-specific error-
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handling policy.
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***
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NOTE: The function assert_failed() typically should NOT use the stack,
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because stack might be corrupted by the time this function is called.
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Also, assert_failed() is intended to handle catastrophic errors and
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should NOT return.
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***
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Adjusting the CPU Clock Speed
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-----------------------------
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The current setting is to run at 32MHz from the PLL, but the CPU clock
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speed can be modified by editing the file system_stm32l1xx.c.
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***
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NOTE:
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With the default setting of 8MHz external clock (HSE_VALUE=8000000), the
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SystemCoreClockUpdate() routine in system_stm32l1xx.c sets the
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SystemCoreClock variable to 32000000 (32MHz). However, the NUCLEO-L152RE
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board appears to run actually only at 16MHz. As a quick fix, the
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projects in the qpc\examples directory set the HSE_VALUE to only 4MHz
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(HSE_VALUE=4000000) in the command-line options to the compiler, to match
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the reporeted SystemCoreClock to the actual speed of the clock (16MHz).
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At this point it is not clear why the CPU clock is set to only half of the
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expected speed.
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***
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