Hi guys, I encountered a problem with a failed BIOS update. So, I searched online about how BIOS firmware is stored and why these issues might occur. I found that NOR Flash is commonly used for storing BIOS, but I had never learned about it before.
Can someone tell me What is a NOR Flash? What are the types of NOR Flash? What are the differences between NAND and NOR Flash?
NOR Flash is a non-volatile memory that retains data even when the power is turned off. Additionally, the design of NOR Flash allows each memory cell to be accessed independently, making it well-suited for storing code, such as firmware and operating systems.
Common Examples of NOR Flash Memory:
BIOS/UEFI Firmware: The BIOS or UEFI firmware on the motherboard is typically stored in NOR Flash. This firmware is responsible for booting the computer and managing the interaction between the hardware and the operating system.
Firmware in Solid-State Drives (SSDs) : Some SSDs use NOR Flash to store control firmware, which manages the reading, writing, and storage processes of data.
Embedded Controllers: Many computer peripherals, such as printers, routers, and security cameras, use NOR Flash to store controller firmware, facilitating the startup and operation of the devices.
In terms of the lifespan of NOR Flash, normally, NOR Flash has high durability and can withstand thousands to tens of thousands of write/erase cycles. In general, the write durability of NOR Flash is usually between 10,000 and 100,000 times.
Types of NOR flash:
Parallel NOR Flash: Data is transmitted through a parallel interface, allowing multiple data lines to transfer data simultaneously, providing a higher data transfer rate. It typically has a high write or erase cycle, making it suitable for applications that require frequent updates, such as BIOS and firmware storage.
Serial NOR Flash: Data is transmitted using a serial interface (such as SPI), where data is transmitted one bit at a time, occupying fewer pins. Although the speed is relatively slower, the power consumption is lower, making it suitable for space-constrained devices like sensors and wearable devices.
SPI NOR Flash: Uses the Serial Peripheral Interface (SPI) standard, offering faster transfer speeds and lower pin requirements. It is widely used in various embedded systems and low-power devices.
NAND takes a series structure, while NOR uses a parallel structure. Both are non-volatile memory that can retain data even when power is off, making them essential in various electronic devices. Let’s look at the differences between NAND and NOR Flash.
First, they have different data access methods. NOR Flash supports random access, allowing data to be read one byte at a time, which is advantageous for reading small amounts of data. NAND Flash, however, primarily employs block access, requiring data to be read and written in blocks, making it suitable for handling large amounts of data.
Secondly, they differ in speed. NOR Flash has a faster read speed, but its write and erase speeds are slower. In contrast, NAND Flash has slower read speeds but typically offers faster write and erase speeds.
They also vary in application scenarios. NOR Flash is often used in devices that require quick reading and execution of code, such as BIOS, UEFI firmware, and embedded systems. However, NAND Flash is widely used in high-capacity storage devices, such as USB flash drives, solid-state drives (SSDs), and mobile storage, primarily for storing data and files.
I got it, thanks all guys!