Algorithm Functions

Blank Check

The following functions are available for creating new Flash programming algorithms:

Function Name Indication Description
BlankCheck optional Check and compare patterns.
EraseChip optional Delete entire Flash memory content.
EraseSector mandatory Delete Flash memory content of a specific sector.
Init mandatory Initialize and prepare device for Flash programming.
ProgramPage mandatory Write the application into the Flash memory.
UnInit mandatory De-initialize the microcontroller after one of the Flash programming steps.
Verify optional Compare Flash memory content with the program code.

The following diagrams show how the functions of the Flash Programming Algorithms are executed by a development tool.

The Flash Erase sequence is executed to erase the Flash content.

FlashErase.png
Flash Erase

The Flash Program sequence is executed to program the Flash memory.

FlashProgram.png
Flash Program

The Flash Verify sequence is executed to verify the content after flash programming.

FlashVerify.png
Flash Verify

 


BlankCheck

int BlankCheck (unsigned long adr, unsigned long sz, unsigned char pat);
Parameters
adrBlock start address
szBlock size in bytes
patPattern to compare
Returns
status information:
  • 0 when the block content is equal to the pattern pat.
  • 1 when the block content differs from the pattern pat.

The function BlankCheck can be used to check whether the specified block is empty, or whether the content is equal to a specific pattern defined in the argument pat.

The argument adr specifies the start address of the block that is to be verified.

The argument sz specifies the size of the block that is to be verified.

Code Example

int BlankCheck (unsigned long adr, unsigned long sz, unsigned char pat) {
unsigned long i, j, k;
// Recalculate address for External SDRAM addresses
if (adr >= SDRAM_START)
adr = adr - SDRAM_START + USER_OFFSET;
for (i = 0; i < sz; i += 256) {
// Read 256 bytes
ReadPage_HW (adr+i, 256, &rd_buf[0]);
// Determine size to compare
if ((sz-i) >= 256) k = 256;
else k = (sz-i);
// Check up to 256 bytes if equal to pattern "pat"
for (j = 0; j < k; j++)
if (rd_buf[j] != pat) return (1); // Memory is not blank
}
return (0); // Memory is blank
}

 


EraseChip

int EraseChip (void);
Returns
status information:
  • 0 on success.
  • 1 on failure.

The function EraseChip deletes the content of the entire Flash memory. It is invoked whenever the uVision menu Flash - Erase is used, or whenever an attempt is made to download the program to Flash and the option Erase Full Chip has been set in the Flash Download Setup dialog. If this function is missing in the Flash Programming Algorithm, the EraseSector function is executed until the entire content of the Flash memory area has been deleted.

Code Example

int EraseChip (void) {
FLASH->CR |= FLASH_MER; // Mass Erase Enabled
FLASH->CR |= FLASH_STRT; // Start Erase
while (FLASH->SR & FLASH_BSY) {
IWDG->KR = 0xAAAA; // Reload IWDG
}
FLASH->CR &= ~FLASH_MER; // Mass Erase Disabled
return (0); // Done
}

 


EraseSector

int EraseSector (unsigned long adr);
Parameters
adrSector address
Returns
status information:
  • 0 on success.
  • 1 on failure.

The function EraseSector deletes the content of the sector starting at the address specified by the argument adr. The function is invoked whenever the uVision menu Flash - Erase is used, or whenever an attempt is made to download the program to Flash and the option Erase Sectors has been set in the Flash Download Setup dialog.

Code Example

int EraseSector (unsigned long adr) {
FLASH->CR |= FLASH_PER; // Page Erase Enabled
FLASH->AR = adr; // Page Address
FLASH->CR |= FLASH_STRT; // Start Erase
while (FLASH->SR & FLASH_BSY) {
IWDG->KR = 0xAAAA; // Reload IWDG
}
FLASH->CR &= ~FLASH_PER; // Page Erase Disabled
return (0); // Done
}

 


Init

int Init (unsigned long adr, unsigned long clk, unsigned long fnc);
Parameters
adrDevice base address
clkClock frequency (Hz)
fncFunction code
Returns
status information:
  • 0 on success.
  • 1 on failure.

The function Init initializes the microcontroller for Flash programming. It is invoked whenever an attempt is made to download the program to Flash.

The argument adr specifies the base address of the device.

The argument clk specifies the clock frequency for prgramming the device.

The argument fnc is a number:

  • 1 stands for Erase.
  • 2 stands for Program.
  • 3 stands for Verify.

Thus, different initialization sections can be implemented for each individual Flash programming step.

Code Example

int Init (unsigned long adr, unsigned long clk, unsigned long fnc) {
// Zero Wait State
FLASH->ACR = 0x00000000;
// Unlock Flash
FLASH->KEYR = FLASH_KEY1;
FLASH->KEYR = FLASH_KEY2;
// Test if IWDG is running (IWDG in HW mode)
if ((FLASH->OBR & 0x04) == 0x00) {
// Set IWDG time out to ~32.768 second
IWDG->KR = 0x5555; // Enable write access to IWDG_PR and IWDG_RLR
IWDG->PR = 0x06; // Set prescaler to 256
IWDG->RLR = 4095; // Set reload value to 4095
}
return (0);
}

 


ProgramPage

int ProgramPage (unsigned long adr, unsigned long sz, unsigned char *buf);
Parameters
adrPage start address
szPage size
bufData to be written
Returns
status information:
  • 0 on success.
  • 1 on failure.

The function ProgramPage is used to write code into the Flash memory. It is invoked whenever an attempt is made to download a program to Flash.

The argument adr specifies the start address of the page that is to be programmed.

The argument sz specifies the size of the page that is to be programmed.

The argument buf points to the buffer containing the data to be programmed.

Code Example

int ProgramPage (unsigned long adr, unsigned long sz, unsigned char *buf) {
sz = (sz + 1) & ~1; // Adjust size for Half Words
while (sz) {
FLASH->CR |= FLASH_PG; // Programming Enabled
M16(adr) = *((unsigned short *)buf); // Program Half Word
while (FLASH->SR & FLASH_BSY);
FLASH->CR &= ~FLASH_PG; // Programming Disabled
// Check for Errors
if (FLASH->SR & (FLASH_PGERR | FLASH_WRPRTERR)) {
FLASH->SR |= FLASH_PGERR | FLASH_WRPRTERR;
return (1); // Failed
}
// Go to next Half Word
adr += 2;
buf += 2;
sz -= 2;
}
return (0); // Done
}

 


UnInit

int UnInit (unsigned long fnc);
Parameters
fncFunction code
Returns
status information:
  • 0 on success.
  • 1 on failure.

The function UnInit de-initializes the microcontroller and is invoked at the end of an erasing, programming, or verifying step.

The argument fnc is a number:

  • 1 stands for Erase.
  • 2 stands for Program.
  • 3 stands for Verify.

Thus, different de-initialization sections can be implemented for each individual Flash programming step.

Code Example

int UnInit (unsigned long fnc) {
// Lock Flash
FLASH->CR |= FLASH_LOCK;
return (0);
}

 


Verify

unsigned long Verify (unsigned long adr, unsigned long sz, unsigned char *buf);
Parameters
adrStart address
szSize in bytes
bufData to be compared
Returns
status information:
  • the sum of (adr+sz) - on success.
  • any other number - on failure, and represents the failing address.

The function Verify compares the content of the Flash memory with the program code *buf.

The argument adr specifies the start address for the verification.

The argument sz specifies the size of the verification.

The argument buf points to the buffer containing the data to be verified.

Code Example

unsigned long Verify (unsigned long adr, unsigned long sz, unsigned char *buf) {
unsigned long i, adr_dest, in_page_ofs;
if (adr < block_size) { // Verifying 2-nd level bootloader data
adr_dest = adr + page_usr_size; // skip page 0 of block 0
} else { // Verifying program data
FindBlock(adr, 0);
adr_dest = nand_block_offset + (adr & (block_size-1));
}
in_page_ofs = adr_dest & (page_usr_size-1);
if (ReadPage_HW(adr_dest, page_usr_size, data_buf)) return (1);
for (i=0; i<sz; i++)
if (buf[i] != data_buf[i+in_page_ofs])
break;
return (adr+i);
}