Some basic knowledge of SPI-Flash

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Some basic knowledge of SPI-Flash [Copy link]

1. Different SPIFLASH chips may provide the following erasing methods: sector erase (4KBytes), half block erase (32KBytes), block erase (64KBytes), and chip erase. 2. Different SPIFLASH chips may provide the following programming methods (that is, writing data): page programming (256Bytes), sector programming (4KBytes). 3. If the SPIFLASH has been erased, it does not make much sense to write data such as 0xFF into it, because its characteristic is that the data after erasure is 0xFF. 4. When writing to flash, you can only change the data (bit) from 1 to 0. 5. The characteristic of traditional EEPROM is that it can randomly access and modify any byte, and can write 0 or 1 to each bit. When writing to flash, data (bit) can only be changed from 1 to 0. However, the capacity of traditional EEPROM is limited due to cost, and rarely exceeds 512K. 6.Nor Flash has relatively small capacity and high cost, and basically no bad blocks. The data line and address line are separated, which can realize random addressing and read any byte. Erasing still needs to be done by block. NAND FLASH has large capacity and low cost. Bad blocks often appear, but bad blocks can be marked so that the software can skip them. The data line and address line are reused, and they can be erased by block and read by page.