NAND FLASH SERIAL
NAND FLASH FULL
NAND FLASH SOFTWARE

Then a 5-bit number represents the page address in block (0 to 31) and a 13-bit number is block address (0 to 4095 for this flash). Then the column is an 8-bit number (0 to 255 for A, B and 0 to 15 for C). For NAND512W3A, there is a different read command for each of the areas ( 0x00 for first half - A, 0x01 for second half - B and 0x50 for spare - C). The address must contain the column, the page and the block. The operation is particularly useful when a portion of a block is updated and the rest of the block needs to be copied to the newly assigned block.

copy back program РІР‚вЂњ copy the data stored in one page and reprogram it in another page, without using an additional memory device.

partial page programming РІР‚вЂњ up to three consecutive program operations are allowed in a page without needing to erase the block and program all pages of that block.

NAND FLASH FULL

I donРІР‚в„ўt know if, internally, the full page is copied to buffer or only the requested columns

random read РІР‚вЂњ you can start reading from any column of the page.

This flash chip has some additional features when compared to the standard model: A block is a collection of 32 pages and there are a total of 4096 blocks in this flash.

Note that the main area of the page is divided in two halves. It is a small page device with 528 bytes/page. The above illustration is specific to my NAND512W3A chip. The pointer is usually limited to a block, but for some chips it may be able to address the whole chip. It is doable with Arduino for small page devices.Р”Р„n auto-incrementing address pointer is used to read large amounts of data without sending a new address to flash chip before any read operation. This means that before new data can be programmed into a page that already contains data, the current contents of the page must be either stored at the host (read and kept in RAM of the controller) or moved to a new, erased page of the flash.

Any cells that have been set to 0 by programming can only be reset to 1 by erasing the entire block. The block is important too, because it is the smallest unit that can be erased. Thus, the page is the elementary unit of operation for a NAND flash (the smallest unit that you read or write). When reading, data is transfer from NAND cells of a page to this register, while when programming, data is transferred to cells from this register. The chip has a corresponding page register (buffer).

NAND FLASH SOFTWARE

The main area of the array is used to store data whereas the spare area is typically used to store Error correction Codes, software flags or Bad Block identification. The page is divided into one or more main areas and a spare area (i.e., the page of a small page device holds 512 bytes in the main area and 16 bytes in the spare area). You will find small page devices (512+16 bytes/page) and large pages devices (2048+64 bytes/page). Without getting into too much detail regarding the physical structure of the NAND flash, itРІР‚в„ўs important to know that multiple cells make a page. These are connected in a two-dimensional grid, where columns are word lines and rows are bit lines. The smallest unit of the flash is a cell, a floating gate transistor (FGT), which is the element which holds a bit of information (0 or 1). I must say I have no prior experience with NAND memory chips and this is the first time IРІР‚в„ўm ever attempting this.Р”В«efore writing the code, we must have a basic understanding of the memory organization in a NAND flash.

NAND FLASH SERIAL

Now I will attempt to read data from the memory and transfer it to PC over serial port. In the previous posts I wired the NAND to a 3.3V Arduino and wrote a basic sketch to communicate with the flash chip and read its ID register. But for common usage, such a slow and limited microcontroller shall not be used for this purpose. The ATmega328 Arduino is way too slow to read and transfer large amounts of data. Although I found out it is possible, it is not quite practical. An Arduino sketch that reads pages and blocks from NAND Flash memory and prints data to serial portР”Р„ while ago I decided to see if it is possible to read data from a NAND flash memory chip using an Arduino.

Nand flash