Flash Memory Library

This library provides routines for accessing microcontroller Flash memory. Note that prototypes differ for MCU to MCU due to the amount of Flash memory.

Important :

Due to the AVR family Flash specifics, Flash library is MCU dependent. Since some AVR MCU's have more or less than 64kb of Flash memory, prototypes may be different from chip to chip.
Please refer to datasheet before using Flash library.
When writting/erasing memory bear in mind that the memory is divided into pages; Size of the page is defined in the __FLASH_PAGE_SIZE constant (in program words) in the definition file of the appropriate MCU.
Writing/erasing memory is possible only from the boot section of the Flash memory.

FLASH_Read_Byte

Prototype	' for MCUs with 64kb of Flash memory or less sub function FLASH_Read_Byte(dim address as word) as byte ' for MCUs with Flash memory larger than 64kb sub function FLASH_Read_Byte(dim address as longword) as byte
Returns	Returns data byte from Flash memory.
Description	Reads data from the specified `address` in Flash memory.
Requires	Nothing.
Example	' for MCUs with Flash memory larger than 64kb dim tmp as longword ... tmp = Flash_Read(0x0D00) ...

FLASH_Read_Bytes

Prototype	' for MCUs with 64kb of Flash memory or less sub procedure FLASH_Read_Bytes(dim address as word, dim buffer as ^byte, dim NoBytes as word) ' for MCUs with Flash memory larger than 64kb sub procedure FLASH_Read_Bytes(dim address as longword, dim buffer as ^byte, dim NoBytes as word)
Returns	Nothing.
Description	Reads number of data bytes defined by `NoBytes` parameter from the specified `address` in Flash memory to variable pointed by `buffer`.
Requires	Nothing.
Example	'for MCUs with Flash memory larger than 64kb const F_ADDRESS as longint = 0x200 dim dat_buff[32] as word ... FLASH_Read_Bytes(F_ADDRESS,dat_buff, 64)

FLASH_Read_Word

Prototype	' for MCUs with 64kb of Flash memory or less sub function FLASH_Read_Word(dim address as word) as word ' for MCUs with Flash memory larger than 64kb sub function FLASH_Read_Word(dim address as longword) as word
Returns	Returns data word from Flash memory.
Description	Reads data from the specified `address` in Flash memory.
Requires	Nothing.
Example	' for MCUs with Flash memory larger than 64kb dim tmp as longword ... tmp = Flash_Read(0x0D00) ...

FLASH_Read_Words

Prototype	' for MCUs with 64kb of Flash memory or less sub procedure FLASH_Read_Words(dim address as word, dim buffer as ^word, dim NoWords as word) ' for MCUs with Flash memory larger than 64kb sub procedure FLASH_Read_Words(dim address as longword, dim buffer as ^word, dim NoWords as word)
Returns	Nothing.
Description	Reads number of data words defined by `NoWords` parameter from the specified `address` in Flash memory to variable pointed by `buffer`.
Requires	Nothing.
Example	'for MCUs with Flash memory larger than 64kb const F_ADDRESS as longint = 0x200 dim dat_buff[32] as word ... FLASH_Read_Bytes(F_ADDRESS,dat_buff, 64)

FLASH_Write_Page

Prototype	sub procedure FLASH_Write_Page(dim address as word, dim dData as ^word) ' for XMEGA family of MCUs sub procedure FLASH_Write_Boot_Page(dim address as word, dim wData as ^word) sub procedure FLASH_Write_Application_Page(dim address as word, dim wData as ^word) sub procedure FLASH_Erase_Write_Application_Page(dim address as word, dim wData as ^word) sub procedure FLASH_Erase_Write_Boot_Page(dim address as word, dim wData as ^word)
Returns	Nothing.
Description	Writes a data array pointed to by `dData` parameter to the specified `address` in Flash memory. For XMEGA family of MCU's you can write to the both boot and application data section. Also, you can erase the appropriate page prior to writing. Parameters : `address:` address of the page used for writting. `dData:` pointer to a data array which is being written.
Requires	Nothing.
Example	dim WRITE_ADDRESS as word dim dat_buff[8] as word ... main: WRITE_ADDRESS = 0x200 FLASH_Read_Words(WRITE_ADDRESS,dat_buff) end.

FLASH_Erase_Page

Prototype	sub procedure FLASH_Erase_Page(dim address as word) ' for XMEGA family of MCUs sub procedure FLASH_Erase_Boot_Page(dim address as word) sub procedure FLASH_Erase_Application_Page(dim address as word)
Returns	Nothing.
Description	Erases specified page in the Flash memory. For XMEGA family of MCU's you can erase both boot and application data section. Parameters : `address:` address of the page being erased.
Requires	Nothing.
Example	dim ERASE_ADDRESS as word ... main: WRITE_ADDRESS = 0x200 FLASH_Read_Words(ERASE_ADDRESS) end.

Library Example

The example demonstrates simple write to the flash memory for AVR, then reads the data and displays it on PORTB and PORTD.

Copy Code To Clipboard

program Flash_MCU_test

const F_ADDRESS as longint = 0x200

const data_ as word[32] = (                               ' constant table
  0x0000,0x0001,0x0002,0x0003,0x0004,0x0005,0x0006,0x0007,
  0x0008,0x0009,0x000A,0x000B,0x000C,0x000D,0x000E,0x000F,
  0x0000,0x0100,0x0200,0x0300,0x0400,0x0500,0x0600,0x0700,
  0x0800,0x0900,0x0A00,0x0B00,0x0C00,0x0D00,0x0E00,0x0F00
 ) org 0x200

dim counter as byte
    word_ as word
    dat_buff as word[32]
    'dat_buff_ as word[32]
main:
  DDRD = 0xFF                              ' set direction to be output
  DDRB = 0xFF                              ' set direction to be output
  word_ = data_[0]                         '  link const table

  counter = 0
  while ( counter < 64 )                            ' reading 64 bytes in loop
    PORTD = FLASH_Read_Byte(F_ADDRESS + counter)    ' demonstration of reading single byte
    Inc(counter)
    PORTB = FLASH_Read_Byte(F_ADDRESS + counter)    ' demonstration of reading single byte
    Inc(counter)
    Delay_ms(200)
  wend

  FLASH_Read_Bytes(F_ADDRESS, @dat_buff, 64)        ' demonstration of reading 64 bytes
  for counter = 0 to 31
    PORTD = dat_buff[counter]                       ' output low byte to PORTD
    PORTB = word((dat_buff[counter] >> 8))          ' output higher byte to PORTB
    Delay_ms(200)
  next counter

  counter = 0
  while (counter <= 63)                             ' reading 32 words in loop
    word_  = FLASH_Read_Word(F_ADDRESS + counter)   ' demonstration of reading single word
    PORTD  = word_                                  ' output low byte to PORTD
    PORTB  = Hi(word_)' >> 8)                       ' output higher byte to PORTB
    counter = counter + 2
    Delay_ms(200)
  wend

  FLASH_Read_Words(F_ADDRESS, @dat_buff, 32)        ' demonstration of reading 64 bytes
  for counter = 0 to 31
    PORTD = dat_buff[counter]                       ' output low byte to PORTD
    PORTB = word((dat_buff[counter] >> 8))          ' output higher byte to PORTB
    Delay_ms(200)
  next counter
end.

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