tutorial ftl - androbenchcsl.skku.edu/uploads/ice3028s14/lab3-tutorial.pdf3 5 … 4151 1 block. ......
TRANSCRIPT
Sejun Kwon
Computer Systems Laboratory
Sungkyunkwan University
http://csl.skku.edu
Tutorial FTL
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 2
Contents
▪ NAND Flash Memory
▪ NAND Flash Operation
▪ NAND Flash Architecture
▪ NAND Controller
▪ Tutorial FTL
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 3
NAND Flash Memory
▪ K9LCG08U1M (Dual die)
• Samsung 35 nm 2-bit MLC flash
• 16 sectors per page (8 KB + 640 B)
• 128 pages per block (1 MB + 80 KB)
• 4096 + 56 blocks per die
• Page read : 250 us
• Page program : 1.3 ms
• Block erase : 1.5 ms
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 4
NAND Flash Memory
▪ NAND Flash Code Information
• http://www.samsung.com/global/business/semiconductor/support/label-code-info/code-info/memory-component
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 5
0
NAND Flash Memory
▪ NAND Flash Organization
Page Buffer
0
2
4
…
4150
Die
1 (“H
igh”)
Pla
ne 0
Die
0 (“L
ow
”)
Page Buffer
1
3
5
…
4151
Pla
ne 1
Block
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 6
NAND Flash Memory
▪ NAND Flash Organization
0
1
2
…
127
Data (8KB) Spare (640B)
Block (1MB + 80KB)
Page (8KB + 640B)
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 7
NAND Flash Operation
▪ Page read
• Cell -> Page Buffer -> RAM
▪ Page program
• RAM -> Page Buffer -> Cell
▪ Page copy-back
• Cell (Src) -> Page Buffer -> Cell (Dst)
▪ Block erase
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 8
NAND Flash Configuration
▪ Channel / Way
8 Way
4 C
hannel
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 9
NAND Flash Configuration
▪ Jasmine Firmware abstracts channel and way to “bank”
▪ 4way * 2 channel = 8 banks
▪ bank number = physical page number % number of banks
▪ Each bank has blocks
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 10
NAND Flash Configuration
▪ Banks share the same IO bus
▪ Each bank can perform cell operation in parallel
• Cell to Page Buffer operation, Block erase
▪ Barefoot has only 4 R/B signal inputs per channel
• A0 and A4 are tied together
• Maximum 4 way interleaving
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 11
NAND Flash Configuration
Ch A/BBank 0(4)
Ch C/DBank 3(7)
Ch A/BBank 2(6)
Ch C/DBank 1(5)
Ch A/BBank 1(5)
Ch A/BBank 3(7)
Ch C/DBank 2(6)
Ch C/DBank 0(4)
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 12
NAND Flash Configuration
▪ 2 Plane operation, 16 bit IO program
• 33 44 55 66 ………… 77 88 99 AA …………
Die 0 (Low) Die 1 (High)
Plane 0 Plane 1 Plane 0 Plane 1
... ... ... ...
77 99 .. 88 AA ..44 66 ..33 55 ..
Block 0 Block 1 Block 0 Block 1
16KB 16KB
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 13
NAND Flash Controller
▪ To issue NAND Flash operation
• Defined in ./include/flash.h
FC_COL_ROW_READ_OUTFC_COL_ROW_IN_PROGFC_COPYBACK
FO_PFO_EFO_B_SATA_WFO_B_SATA_R
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 14
NAND Flash Controller
▪ To issue NAND Flash operation
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 15
Tutorial FTL
▪ ./ftl_tutorial
• ftl.c, ftl.h
▪ Page Mapping FTL
• Write data from DRAM to NAND
• Read data from NAND to DRAM
• But no garbage collection
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 16
Page Mapping Table
▪ LPN to PPN map
• LPN: Logical Page Number
- LPN = LBA / Sectors Per Page
• PPN: Physical Page Number
Index 0 1 2 3 … 2097151
Value 100 256 0 INVALID … 20000
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 18
Write Operation
▪ ./ftl_tutorial/ftl.c
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 19
Write Operation
Old Page (32KB)
Left hole read Write hole readWriteDRAM
NAND
New Page (32KB)NAND
For Not In-Place Update
For Partial Write
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 20
Write Operation
▪ ./ftl_tutorial/ftl.c
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 21
Write Operation
▪ ./ftl_tutorial/ftl.c
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 22
NAND Flash Operation
▪ ./target_spw/flash.c
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 23
NAND Flash Operation
▪ ./target_spw/flash.c
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 24
NAND Flash Operation
▪ ./target_spw/flash_wrapper.c
ICE3028: Embedded Systems Design (Spring 2014) – Jin-Soo Kim ([email protected]) 25
Error Handling
▪ ./ftl_tutorial/ftl.c
ftl_open()
