flash-memory

is someone in the kow about write accesses on nowadays large NAND flash chips? What is the minimal granularity for writes? I have a microcontroller flash here which requires at least 1 and at most 4 words (16-bit words that is) to be fed to the write statemachine at once. I think that the large (> 1 Gbit) flashes behave differently here for write performance reasons. slarti So to be clear, to write a 1 bit you have to clear a whole block of memory, to write a 0 bit you only have to write one memory location. Are you talking about a one time write (changing some of the bits from a 1 to a 0

We are using MT29F8G08ABABA in our DM365 based custom board. We are using NAND boot. RootFS is in UBIFS format, Below is basic achitecture of the NAND. I am using following commands to create ubifs, $(UBIFS_PATH)/mkfs.ubifs -r $(TARGET_FS) -m 4096 -e 520192 -c 75 -o ubifs.img $(UBIFS_PATH)/ubinize -o $(SYSTEM_CFG)_$(HARDWARE_CFG)_ubifs -m 4096 -p 512KiB $(HARDWARE_CFG)_ubinize.cfg dm368_ubinize.cfg content is as follows, [ubifs] mode=ubi image=ubifs.img vol_id=0 vol_size=37888KiB vol_type=dynamic vol_name=rootfs vol_flags=autoresize Then i put this ubifs to NAND using following commands, loady

I am working on an embedded application that uses NAND flash for storage. As it looks now, we won't use Linux or any other RTOS. The application must handle unexpected power downs. We have been looking on different file system solutions, including YAFFS2, JFFS2, FAT+FTL as well as solutions from HCC Embedded . I have heard FAT+FTL is a normal choice, but I am worried about data loss in case of unexpected power downs as well as performance. Would be grateful if anyone could share insights and experience about this FAT-FTL is a "normal choice", but not necessarily a good choice. YAFFS2 is newer

So I can't write to internal flash memory directly after erasing it. If there's no erase operation before write operation, then I can. Any ideas as to why? Programming function returns 'successful write' value, but when looking at memory, no data is written. Here's the code: uint32_t pageAddress = 0x08008000; uint16_t buffer = 0xAAAA; HAL_FLASH_Unlock(); FLASH_PageErase(pageAddress); HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, pageAddress, buffer); HAL_FLASH_Lock(); I've tried locking the memory between erasing and programming it, creating a delay between these operations, that doesn't help. The

I am new at embedded system programming. I am working on a device that uses an 8051 chipset. I have noticed in the sample programs that when defining variables, sometimes they use the keyword xdata. like this... static unsigned char xdata PatternSize; while other times the xdata keyword is omitted. My understanding is that the xdata keyword instructs the compiler that that variable is to be stored in external, flash, memory. In what cases should I store variables externally with xdata? Accessing those variables takes longer, right? Values stored using xdata do not remain after a hard reset of