SSD-master control, flash memory and firmware (transfer)

• SSD
  • SSD Solid State Drives
  • Hard disk made with solid-state electronic memory chip array
  • Composed of control unit and storage unit
  • Manufacturers only need to buy NAND memory and cooperate with the appropriate control chip to manufacture solid state drives.
  • NAND: computer flash memory device
  • There are two types of storage media:
    • Based on flash memory: using FLASH chips as storage media, such as notebook hard drives, U disks, etc., the number of erasing and writing is generally about 3000
    • Based on DRAM: narrow application range, non-mainstream equipment
  • basic structure
    • Flash-based solid-state drives are the main category with simple internal structure
    • The main body is essentially a PCB board
    • PCB: Printed Circuit Board: Printed Circuit Board
    • The most basic accessories on the PCB are the control chip, the cache chip (no low-end), and the flash memory chip (store data)
    • Flash memory chips are divided into SLC, MLC, TCL
  • The main factors that affect the performance of solid state drives are: main control chip, NAND flash memory media and firmware
    • Firmware: Firmware
      • Refers to the program written in EROM (Erasable and Programmable Read Only Memory) or EEPROM (Electrically Erasable and Programmable Read Only Memory)
      • Refers to the device driver stored inside the device
      • Through the firmware, the operating system can realize the operation of a specific machine according to the standard device driver
      • Firmware serves as the most basic and lowest level software for a system
      • Users can upgrade through specific refresh procedures
      • For example, the BIOS (Basic Input Output System) on the motherboard is the firmware
      • It was originally written on the ROM, and then it was immutable. Later, EPROM was used, and the rewritable programming ROM was used to upgrade the firmware.
• SSD analysis
  • The main components of SSD: main control chip, NAND flash memory chip, firmware algorithm
  • HDD (Hard Disk Drive) runs on mechanical drive heads, motors, platters, magnetic head rocker arms, etc. 95% of the time is consumed on the rocker arms of mechanical parts
  • SSD uses integrated circuit PCB card to replace traditional mechanical hard disk
  • Master
    • Embedded chip, similar to CPU
    • Mainstream controller: Marvell/SandForce/Samsung/Indilinx
  • firmware
    • The main controller performs signal processing, bad block management, etc. according to the program in the firmware
  • Flash memory
    • SLC、MLC、TLC
    • SLC particles: each storage unit represents 1bit, MLC-2bit, TLC-3bit
    • The more the number of bits stored in a storage unit, the greater the natural capacity, but it will reduce reliability, durability and performance
• SSD interface
  • STAT 6Gbps
    • A parameter standard of STAT Revision 3.0, relative to 2.0
    • The exact name is STAT III, the interface speed is 6Gbps
  • mSTAT
    • Product specification of new mini-SATA (mSTAT) interface controller developed by STAT Association
    • Widely used in ultrabooks, business notebooks and other notebook computers that pursue miniaturization
    • The speed is still 6Gbps
  • M.2
    • M.2 formerly known as NGFF interface
    • A new generation interface standard tailored for Ultrabook Ultrabook, which replaces the mSTAT interface
    • Transmission performance is far better than mSTAT. As the bottleneck of the STAT interface continues to emerge, motherboard manufacturers begin to reserve M.2 interface
    • M.2 interface can support STAT and PCI-E channels at the same time, the latter is easier to increase the speed
  • PCI-E
    • At the beginning of the development of STAT interface SSD, PCI-E interface SSD appeared
    • Because no matter what interface other SSD uses, it will eventually move from SATA to native PCI-E
    • PCI-E interface SSD is directly in place in one step
    • PCI-E was initially mostly used in the enterprise-level market, and the cost was relatively high
  • STAT Express
    • Transformed through STAT 6Gbps interface, not popular
    • Backward compatible with STAT 6Gbps interface