writing half word 16 bits on flash stm32f429ZI

Question

Posted on May 23, 2018 at 10:05Hello evry body , i can write a byte on flash of stm32f429ZI WÄ°TH success . for info i use nucleo 144 and sector 23 the last sector .for example :with these adresses uint32_t locip1_adress=0x081E0001;//LAST sector for STM32429ZI sector 23uint32_t locip2_adress=0x081E0002;//LAST sector for STM32429ZI sector 23uint32_t locip3_adress=0x081E0003;//LAST sector for STM32429ZI sector 23uint32_t locip4_adress=0x081E0004;//LAST sector for STM32429ZI sector 23uint32_t remip1_adress=0x081E0005;//LAST sector for STM32429ZI sector 23uint32_t remip2_adress=0x081E0006;//LAST sector for STM32429ZI sector 23uint32_t remip3_adress=0x081E0007;//LAST sector for STM32429ZI sector 23uint32_t remip4_adress=0x081E0008;//LAST sector for STM32429ZI sector 23uint32_t ROV_min_adress=0x081E0009;//LAST sector for STM32429ZI sector 23 this data needs two bytesuint32_t ROV_max_adress=0x081E00B;//LAST sector for STM32429ZI sector 23 this data needs two bytes/* Unlock the Flash to enable the flash control register access *************/ HAL_FLASH_Unlock();  /* Fill EraseInit structure*/ EraseInitStruct.TypeErase = FLASH_TYPEERASE_SECTORS; EraseInitStruct.VoltageRange = FLASH_VOLTAGE_RANGE_3; EraseInitStruct.Sector = FLASH_SECTOR_23; EraseInitStruct.NbSectors = 1; //you need to erase entire sector before write anything HAL_FLASHEx_Erase(&EraseInitStruct, &SECTORError);//we need to erase the sector before writeHAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, locip1_adress,locip1);//write one byte HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, locip2_adress,locip2);//write one byte HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, locip3_adress,locip3);//write one byte HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, locip4_adress,locip4);//write one byte  HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, remip1_adress,remip1);//write one byte// we need to write also all other parameter because we delete all sector 23  HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, remip2_adress,remip2);//write one byte HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, remip3_adress,remip3);//write one byte HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, remip4_adress,remip4);//write one byte  HAL_FLASH_Program(FLASH_TYPEPROGRAM_HALFWORD,ROV_min_adress,Rover_ID_min[0]);//write one 16 bit  HAL_FLASH_Program(FLASH_TYPEPROGRAM_HALFWORD,ROV_max_adress,Rover_ID_max[0]);//write one 16 bit   HAL_FLASH_Lock();But in THE HALFWORD writing i have prblm with 16 bit writing looks these adresses are not accepted uint32_t ROV_min_adress=0x081E0009;  ----> in my idea for one word ill use 0x081E0009+ 0x081E000A Two bytes --->is it rightuint32_t ROV_max_adress=0x081E00B;-----> WÄ°LL use 0x081E000B+0x081E000C  two bytes but the data at the reading of  ROV_max_adress are wrong strangely ??how should i select the adresses separation between them for writing half word can someone give me an example . thanks could not find detail about mem data adresses in detail .

Tilen MAJERLE · Accepted Answer

Posted on May 24, 2018 at 14:39 Hello  doumandjisamah‌,  To know when you have 16-bit aligned address, you can check LSB bit which must be 0, thus:  Every address is byte aligned, no matter on LSB bit valueEvery second address is 16-bit (half-word) aligned  0 = 0b0000, 2 = 0b0010, 4 = 0100, 6 = 0b0110Every 4th address is 32-bit (word) aligned, LSB and LSB-1 bits must be 0.  0 = 0b0000;4 = 0b0100;8 = 0b1000  In your case, address 0x081E0009 is odd, LSB =1 => not 16-bit aligned, while 0x081E000A or 0x081E000C is even number,  LSB = 0 => 16-bit aligned.  If we go back to flash write process:  To be able to write in BYTE mode, you may use any valid flash address (LSB don't care)To be able to write in HALF-WORD mode, your address must be 16-bits aligned (LSB must be 0)To be able to write in WORD mode, your address must be 32-bits aligned (LSB and LSB - 1 must be 0)To be able to write in QWORD mode, your address must be 64-bits aligned (LSB, LSB - 1 and LSB - 2 must be 0).  Hope it is clear now.  Best regards,  Tilen

Tilen MAJERLE · Answer

Posted on May 23, 2018 at 10:22 Dear  ‌, please check FLASH_SR register for possible errors when programming. Address must be 16-bits aligned, which is not your case. uint32_t ROV_min_adress=0x081E0009;�? should be uint32_t ROV_min_adress=0x081E0008; //Either 8 and then it will use 8 + 9 bytesuint32_t ROV_min_adress=0x081E000A; //Or A and then it will use A + B bytes�?�? Best regards, Tilen

Sign up

Login with SSO

Login to the community

Login with SSO