view Small_CPU/CPU2-RTE.ld @ 328:4fe5400567e7 I2C_Improvment

Set I2C speed to 88kHz, use digital filter only and reworked idle clock recovery The errata describes a possible problem in operation between 88kHz and 100kHz => Set speed as recommended as work around. Based on reference implementation only one filter should be use. Choice was digital because only drawback is lag of wakeup functionality which is not used I2C communication may be randomly interrupted e.g. by a RTE reset or firmware update => reworked recovery function to get I2C devices in idle state again (Clk and SDA HIGH)
author ideenmodellierer
date Wed, 17 Jul 2019 22:42:15 +0200
parents 321df89d5710
children aa286a4926c2
line wrap: on
line source

/* ---------------------------------------------------------------------------- */
/*                  Em::Blocks embedded development Support                     */
/* ---------------------------------------------------------------------------- */
/* Copyright (c) 2014, EmBlocks                                                 */
/*                                                                              */
/* All rights reserved.                                                         */
/*                                                                              */
/* Redistribution and use in source and binary forms, with or without           */
/* modification, are permitted provided that the following condition is met:    */
/*                                                                              */
/* - Redistributions of source code must retain the above copyright notice,     */
/* this list of conditions and the disclaimer below.                            */
/*                                                                              */
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/* this software without specific prior written permission.                     */
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/* DISCLAIMER:  THIS SOFTWARE IS PROVIDED BY EBLOCKS "AS IS" AND ANY EXPRESS OR */
/* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE   */
/* DISCLAIMED. IN NO EVENT SHALL EMBLOCKS BE LIABLE FOR ANY DIRECT, INDIRECT,   */
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/* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,  */
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/* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */
/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                           */
/* ---------------------------------------------------------------------------- */

/*------------------------------------------------------------------------------
 *      Linker script for running in internal FLASH on the STM32F401RE
 *----------------------------------------------------------------------------*/

/* Entry Point */
ENTRY(Reset_Handler)

OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
OUTPUT_ARCH(arm)
SEARCH_DIR(.)

/* Memory Spaces Definitions */
MEMORY
{
    ROM  (rx) : ORIGIN = 0x08000000, LENGTH = 512K /* 80000 */
    RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 96K
}
/* Linker script to place sections and symbol values. Should be used together
 * with other linker script that defines memory regions FLASH and RAM.
 * It references following symbols, which must be defined in code:
 *   Reset_Handler : Entry of reset handler
 * 
 * It defines following symbols, which code can use without definition:
 *   __exidx_start
 *   __exidx_end
 *   __etext
 *   __data_start__
 *   __preinit_array_start
 *   __preinit_array_end
 *   __init_array_start
 *   __init_array_end
 *   __fini_array_start
 *   __fini_array_end
 *   __data_end__
 *   __bss_start__
 *   __bss_end__
 *   __end__
 *   end
 *   __HeapLimit
 *   __StackLimit
 *   __StackTop
 *   __stack
 */


SECTIONS
{
  .isr_vector 0x08000000 :
  {
  . = ALIGN(4);
    KEEP( *(.isr_vector) ) 
    KEEP(*(.init))
    KEEP(*(.fini))
  } >ROM
  
	/* Place FirmwareData at absolute address */
	.firmware_data 0x08005000:
	{
		cpu2_FirmwareData = 0; 
		KEEP( *(.firmware_data) )
	} > ROM

	.text 0x08005100 :
	{	
		. = ALIGN(4);
		*(.text)           /* .text sections (code) */
		*(.text*)
		*(.eh_frame*)
        . = ALIGN(4); 
  
	} > ROM

/********************** Constant data into ROM memory *********************/
  .rodata :
  {
    . = ALIGN(4);
    *(.rodata)         /* .rodata sections (constants, strings, etc.) */
    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
    . = ALIGN(4);
  } >ROM
  
	.ARM.extab :
	{
		*(.ARM.extab* .gnu.linkonce.armextab.*)
	} > ROM

	__exidx_start = .;
	.ARM.exidx :
	{
		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
	} > ROM
	__exidx_end = .;

  .preinit_array     :
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN( __preinit_array_start = . );
    KEEP( *(.preinit_array*) )
    PROVIDE_HIDDEN( __preinit_array_end = . );
    . = ALIGN(4);
  } >ROM
  
  .init_array :
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN( __init_array_start = . );
    KEEP( *(SORT(.init_array.*)) )
    KEEP( *(.init_array*) )
    PROVIDE_HIDDEN( __init_array_end = . );
    . = ALIGN(4);
  } >ROM
  
  .fini_array :
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN( __fini_array_start = . );
    KEEP( *(SORT(.fini_array.*)) )
    KEEP( *(.fini_array*) )
    PROVIDE_HIDDEN( __fini_array_end = . );
    . = ALIGN(4);
    
    __etext = .;        /* define a global symbols at end of code */
  } >ROM

 /* Used by the startup to initialize data */
 	_sidata = LOADADDR(.data);

	.data : 
	{
		. = ALIGN(4);
		__data_start__ = .;
		_sdata = .;        /* create a global symbol at data start */
    	*(.data)           /* .data sections */
		*(.data*)
		*(vtable)
		. = ALIGN(4);
		/* All data end */
		__data_end__ = .;
	} >RAM AT>ROM

	.bss :
	{
		__bss_start__ = .;
		*(.bss*)
		*(COMMON)
		__bss_end__ = .;
	} >RAM
	
	.heap :
	{
		__end__ = .;
		end = __end__;
		*(.heap*)
		__HeapLimit = .;
	} > RAM

	/* .stack_dummy section doesn't contains any symbols. It is only
	 * used for linker to calculate size of stack sections, and assign
	 * values to stack symbols later */
	.stack_dummy :
	{
		*(.stack)
	} > RAM

	/* Set stack top to end of RAM, and stack limit move down by
	 * size of stack_dummy section */
	__StackTop = ORIGIN(RAM) + LENGTH(RAM);
	__StackLimit = __StackTop - SIZEOF(.stack_dummy);
	PROVIDE(__stack = __StackTop);
	
	/* Check if data + heap + stack exceeds RAM limit */
	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
}