SSD
ssd基本介绍
Contents
SSD Architecture
- SSD is a complete, small system where all componets are soldedred on a PCB and is indpendenty packaged
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| |
| SSD |
| ----------------------------------------------------------- |
| | | |
| ------ | ----- ----- ----------------- ---------- | |
| | | | | | | | | | | | |CH0 -----
| | | | | | | | | | | |---------|Flash|
| | | | | | |----| | | | | | -----
| | | | | | | | ARM Cores | | | | |
| | PCIE | | |PCIE |NVMe | | |-------| Flash | | |
| | Host |---- | |Layer|Layer| | | |Controller| | |CH1 -----
| | | | | | | | | | | |-------- |FLASH|
| | | | | | | ----------------- | | | | -----
| | | | | | | | | | | | |
| | | | | | | | | | | | |
| | | | | | | -------- ---------- | | | . |
| | | | | | | |Internal| | DRAM | | | | . |
| ------- | | | | | Buffer | |Controller| | | | . |
| | ----- ----- -------- ---------- ---------- | . |
| | | | |
| | | ------------ | |
| | | | | | |
| | | |other logic | | |CHn -----
| | | | | |------- |FLASH|
| | | ------------ | | -----
| ----------------------------------|------------------------ |
| | |
| | |
| ----------- |
| | | |
| | DRAM | |
| | | |
| ----------- |
| |
-------------------------------------------------------------------------------Controller功能
- 提供一个接口在host和Flash之间
- 处理来自host的数据，提高数据传输效率以及数据的可靠性。 Controler中包含wear leveling， Garbage colletcion， Bad Block magnagement，ECC，flash interface。
DRAM
- DRAM主要用来作为L2P(Logic to Physical) table mapping，一般配置是1GB NAND FLASH空间对应1MB DRAM
- FW code本省也需要dram空间来运行
- 多余的DRAM空间可以作为host write buffer以及其他的table（比如：Bad Block table， RBTree for good/availbale blocks）
- 帮助实现奇偶校验
其他部分
voltage supervisor 防止2powerloss and brown outs。如果检测到有power loss，那么fw对打断一些特殊操作。
Backup capacitance super caps 可以保证整个drive backup（比如dump entrie dram） tantalum caps 提供一段时间保证program comman完成。
NOR FLASH
- BOOTLOAD(Enumerates the nand, initialized the DRAM)
- Manufacturing data
- Page Table pOINTER(nand lbock that contains the L2P table)
- Error/evnet logs