SRAM

1
10. ???

• ?? ??

2
?????

• ???
• SRAM
• DRAM
• Flash Memory

3
???
4
??????

• ???
• ?????????
• ???????,????????????????.
• ??????
• ????????,?????,?????.

5
??????

• ??????
• RAM (Random Access Memory)
• ROM (Read-Only Memory)
• ??? (volatile) ?
• ??????
• ???????

??? ????
ROM ????? ??
RAM ?? ?
6
RAM
7
RAM ???
???? ?? ??? ???? ??? ??
SRAM SRAM (Static -) ???? ? ?
DRAM DRAM (Dynamic -) ????? ? ? ?
FeRAM FeRAM (Ferroelectric) ???? ? ? ? FeliCa
??? DRAM MRAM (Magnetic) ??? ? ? ? ? ?
??? DRAM RRAM (Resistive) ???? ? ? ? ? ?
??? DRAM PRAM (Phase-change) ???? ? ? ? ? ?
8
RAM ???????
bit-line
RAM Cell
row addr decoder
Word-line
row addr
sense amps
column addr decoder
column addr
data
9
?????

• ?????
• (????)??????
• ????,?????????
• ??????
• 1???4????

10
(CMOS) SRAM
11
SRAM Cell
bit-line
bit-line
word-line
12
SRAM

• ????6T (Transistor) Cell
• ????????? (2T)
• NOT x2 ??????? (4T)
• ????
• nMOS ???????????
• ????? high ????????,
• nMOS ??????????????
• ??????????

13
DRAM

• ????1T-1C
• ????????? (1T)
• ????? (1C)
• ????

1T
1C
14
?????
2/11/2003, http//www.future-fab.com/documents.asp
?grID214d_ID1669
15
DRAM

• C ?????
• ????? 1/2 VDD ????????,
• C ???
• (?????) ltlt (???????)
• ????????????????
• ???
• ?????
• ????,???????????
• ? ??????(??)

1T
1C
16
DRAM

• ??????
• ?????????,??????????
• ????,????(??????)?????

17
?? DRAM

• ?? DRAM
• SDRAM (Synchronous -)
• DDR SDRAM (Double Data Rate -)
• RDRAM (Rambus -)
• XDRDRAM (eXtreme Data Rate -)
• ????? I/F ????
• ???,??????
• ??????????,??????????????

18
??? DRAM

• MRAM,RRAM,PRAM,etc.
• ???????????
• DRAM ??,??/???
• ????
• ???,????????????
• ??????,??????
• ????????????
• ???????,DRAM ??????

19
ROM
20
ROM ???

• ??? ROM
• ???????(??????)

• PROM (Programmable ROM)
• ???????????(?????)

• OTPROM (One-Time PROM)
• 1???????????(???????)

• EPROM (Erasable PROM)
• ???,????????

• UV-EPROM
• ??????

• EEPROM (Electrically Erasable PROM)
• ??????

• Flash Memory
• ????????????? (flash)

21
ROM ???

• ??????????????????

OFF
ON/OFF
ON
ON/OFF
22
ROM ???
OFF
ON
ON
ON
OFF
ON
ON
ON
0
1
NAND ?
1
0
ON
OFF
OFF
OFF
ON
OFF
OFF
OFF
NOR ?
23
EPROM

• ????? (floating gate) ??????
• ????VT ??
• ????VT ??

??????
VT
VT
?????
ctrl gate
ctrl gate
floating gate
source
drain
source
drain
p
n
n
p
n
n
24
??????
25
??????

• ???
• SRAM
• DRAM
• PROM

26
?????

• 1/19
• ??????????????
• (??)
• 3/ 2
• ?? (9001030)