This module contains functions for modifing internal flash memory. More...

Files
file	stm32f103cb_flash.h
	Header file for stm32f103cb FLASH.

Functions
mcu_error	FLASH_clearPage (uint32_t pageNumber)
	Clear a page (1kb) of flash. More...

mcu_error	FLASH_write (uint32_t pageNumber, uint32_t address, uint32_t data)
	Write a single word to flash. More...

mcu_error	FLASH_writes (uint32_t pageNumber, uint32_t address, uint32_t *data, uint16_t size)
	Write multiple words to flash, address incremented automatically. More...

uint32_t	FLASH_read (uint32_t pageNumber, uint32_t address)
	Read a single word from flash memory. More...

mcu_error	FLASH_reads (uint32_t pageNumber, uint32_t address, uint32_t *data, uint16_t size)
	Read multiple words from flash. More...

mcu_error	FLASH_readPage (uint32_t pageNumber, uint32_t *data)
	Read an entire page from flash. More...

uint8_t	FLASH_pageEmpty (uint32_t pageNumber)
	Determine if a given page is empty. More...

uint8_t	FLASH_firstEmptyPage (void)
	Get the first empty page is flash. More...

Detailed Description

This module contains functions for modifing internal flash memory.

The STM32f1x3 has 128kb of programmable flash memory. This space can also be used to store user values at runtime. It has the following restrictions

Bits can only be set from 1 to 0. This means each address can only be used once before it needs to be erased.
Erasing is done at a page level, for this device each page is 1kb
The read and write operations block the CPU.
If a new uploaded program can overwrite existing flash data.

It can be benificial to occasionally clear all flash memory, this ensures the data occupying the flash memory is being used. This can be acheived with "make erase" from program directory.

Flash memory can only be changed from 1 to 0. This means each location needs to be reset with FLASH_clearPage() before it is writted again.

This module provides access to the flash memory. Typically pages toward the module (pages 120 - 127) should be used. The exact location of the free portion not used by code can be found by looking at the "text" section when the program is compiled.

Each page contains 256 words (32 bit) segments which can be used.

Author: Stuart Ianna

Version: 0.1

Date: June 2018

Copyright: GNU GPLv3

Bug:: None

Todo:

Warning: Take note of where data is written. It is possible to overwrite the application code.

Compilers

arm-none-eabi-gcc (15:4.9.3+svn231177-1) 4.9.3 20150529 (prerelease)

Working example.: Notice every time the MCU is flashed or reset the first empty page is incremented by one. This occurs as the program only erases the data needed for the binary. Use "make erase" to clear enitre flash memory of MCU
#include <stm32f103cb_core.h>
#include <coms128.h>
uint32_t readData[3];
uint32_t writeData[2];
int main(void){
uint8_t pageBase;
//Serial setup
USART_setup(USART_1);
USART_setBaud(USART_1,USART_BAUD_115200);
COMS(USART_1);
//Some random data
writeData[0] = 456;
writeData[1] = 789;
//Get the first empty page to use
pageBase = FLASH_firstEmptyPage();
//Should check device is not full
if(pageBase == 0){
printl("No free pages");
//Halt here
while (1);
}
//Print some data to word zero of that page
FLASH_write(pageBase,0,123);
//Print some more data to that page, starting at word 1
FLASH_writes(pageBase,1,writeData,sizeof(writeData));
//Read the data written, starting from word zero
FLASH_reads(pageBase,0,readData,sizeof(readData));
//Print out info
prints("First empty page is page");
printl(pageBase);
printl("Data read");
prints(readData[0]);
prints(readData[1]);
printl(readData[2]);

printl("Done");
while (1);
return 0;
}

Function Documentation

mcu_error FLASH_clearPage ( uint32_t pageNumber )

Clear a page (1kb) of flash.

This needs to be used if the same memory location is used multiple times.

Flash memory can only be changed from 1 to 0. This means each location needs to be reset with FLASH_clearPage() before it is written again.

Parameters

pageNumber The page to clear (0-127)

Warning: It is possible to remove application code with this function.

Returns: Error number as defined in mcu_error, E_FLASH_NOERROR if no error, E_FLASH_PAGE if page is out of range

Definition at line 22 of file stm32f103cb_flash.c.

uint8_t FLASH_firstEmptyPage ( void )

Get the first empty page is flash.

Warning: This doesn't work in conjuction with the USB bootloader, as if the entire contents were erased, the bootloader would be destroyed.

Returns: The first empty page which can be used, returns 0 if no pages are empty.

Definition at line 158 of file stm32f103cb_flash.c.

uint8_t FLASH_pageEmpty ( uint32_t pageNumber )

Determine if a given page is empty.

Parameters

pageNumber The page to check. (0-127)

Warning: This function doesn't check page bounds

Returns

1 if page is empty
0 if page containes data

Definition at line 142 of file stm32f103cb_flash.c.

uint32_t FLASH_read	(	uint32_t	pageNumber,
		uint32_t	address
	)

Read a single word from flash memory.

Parameters

pageNumber	The page to read from. (0-127)
address	The word in that page (0-255)

Returns: The data at the given address

Definition at line 88 of file stm32f103cb_flash.c.

mcu_error FLASH_readPage	(	uint32_t	pageNumber,
		uint32_t *	data
	)

Read an entire page from flash.

Parameters

pageNumber	The page to read from. (0-127)
data	Pointer to a memory container large enough to hold the data

Warning: The size of data must be greater than 256 words ie. uint32_t data[256]

Returns: Error number as defined in mcu_error, E_FLASH_NOERROR if no error, E_FLASH_PAGE if page is out of range

Definition at line 119 of file stm32f103cb_flash.c.

mcu_error FLASH_reads	(	uint32_t	pageNumber,
		uint32_t	address,
		uint32_t *	data,
		uint16_t	size
	)

Read multiple words from flash.

Parameters

pageNumber	The page to read from. (0-127)
address	The word in that page to start from (0-255)
data	Pointer to a memory container large enough to hold the data
size	The size of parameter data

Warning: If size is larger than data, a memeory fault will occur

Returns: Error number as defined in mcu_error, E_FLASH_NOERROR if no error, E_FLASH_PAGE if page is out of range

Definition at line 96 of file stm32f103cb_flash.c.

mcu_error FLASH_write	(	uint32_t	pageNumber,
		uint32_t	address,
		uint32_t	data
	)

Write a single word to flash.

A word can only be written to a location once before FLASH_clearPage() is used to reset the memory location

It is possible to use a word address greater than 255. This means that the data will be located in the next page.

Parameters

pageNumber	The page to write to (0-127)
address	The word in that page (0-255)
data	The data to write to the location

Warning: It is possible to remove application code with this function.

Returns: Error number as defined in mcu_error, E_FLASH_NOERROR if no error, E_FLASH_PAGE if page is out of range

Definition at line 41 of file stm32f103cb_flash.c.

mcu_error FLASH_writes	(	uint32_t	pageNumber,
		uint32_t	address,
		uint32_t *	data,
		uint16_t	size
	)

Write multiple words to flash, address incremented automatically.

A word can only be written to a location once before FLASH_clearPage() is used to reset the memory location

It is possible to use a word address greater than 255. This means that the data will be located in the next page.

Parameters

pageNumber	The page to write to (0-127)
address	The word in that page (0-255)
data	Pointer to the data to write to the location
size	The size of parameter data

Warning: It is possible to remove application code with this function.; If size is larger than data, a memeory fault will occur

Returns: Error number as defined in mcu_error, E_FLASH_NOERROR if no error, E_FLASH_PAGE if page is out of range

Definition at line 61 of file stm32f103cb_flash.c.

Files

Functions

Detailed Description

Function Documentation