參數(shù)資料
型號(hào): HM5225405B
廠商: Hitachi,Ltd.
英文描述: 256M LVTTL interface SDRAM(256M LVTTL接口同步DRAM)
中文描述: 256M LVTTL接口的SDRAM(256M LVTTL接口同步的DRAM)
文件頁數(shù): 12/64頁
文件大小: 802K
代理商: HM5225405B
HM5225165B/HM5225805B/HM5225405B-75/A6/B6
12
DQM Truth Table
(HM5225165B)
CKE
Command
Symbol
n - 1
n
DQMU
DQML
Upper byte (DQ8 to DQ15) write enable/output enable ENBU
H
×
×
×
×
L
×
Lower byte (DQ0 to DQ7) write enable/output enable
ENBL
H
×
L
Upper byte (DQ8 to DQ15) write inhibit/output disable MASKU
H
H
×
Lower byte (DQ0 to DQ7) write inhibit/output disable
Note:
H: V
IH
. L: V
IL
.
×
: V
IH
or V
IL
.
Write: I
DID
is needed.
Read: I
DOD
is needed.
MASKL
H
×
H
DQM Truth Table
(HM5225805B/HM5225405B)
CKE
Command
Symbol
n - 1
n
DQM
Write enable/output enable
ENB
H
×
×
L
Write inhibit/output disable
Note:
H: V
IH
. L: V
IL
.
×
: V
IH
or V
IL
.
Write: I
DID
is needed.
Read: I
DOD
is needed.
MASK
H
H
The SDRAM can mask input/output data by means of DQM, DQMU/DQML.
DQMU masks the upper byte and DQML masks the lower byte. (HM5225165B)
During reading, the output buffer is set to Low-Z by setting DQM, DQMU/DQML to Low, enabling data
output. On the other hand, when DQM, DQMU/DQML is set to High, the output buffer becomes High-Z,
disabling data output.
During writing, data is written by setting DQM, DQMU/DQML to Low. When DQM, DQMU/DQML is set
to High, the previous data is held (the new data is not written). Desired data can be masked during burst read
or burst write by setting DQMU/DQML. For details, refer to the DQM, DQMU/DQML control section of the
SDRAM operating instructions.
相關(guān)PDF資料
PDF描述
HM5225805B 256M LVTTL interface SDRAM(256M LVTTL接口同步DRAM)
HM5225165B 256M LVTTL interface SDRAM(256M LVTTL接口同步DRAM)
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HM5225405B-75 制造商:ELPIDA 制造商全稱:Elpida Memory 功能描述:256M LVTTL interface SDRAM 133 MHz/100 MHz 4-Mword 】 16-bit 】 4-bank/8-Mword 】 8-bit 】 4-bank /16-Mword 】 4-bit 】 4-bank PC/133, PC/100 SDRAM
HM5225405B-A6 制造商:ELPIDA 制造商全稱:Elpida Memory 功能描述:256M LVTTL interface SDRAM 133 MHz/100 MHz 4-Mword 】 16-bit 】 4-bank/8-Mword 】 8-bit 】 4-bank /16-Mword 】 4-bit 】 4-bank PC/133, PC/100 SDRAM
HM5225405B-B6 制造商:ELPIDA 制造商全稱:Elpida Memory 功能描述:256M LVTTL interface SDRAM 133 MHz/100 MHz 4-Mword 】 16-bit 】 4-bank/8-Mword 】 8-bit 】 4-bank /16-Mword 】 4-bit 】 4-bank PC/133, PC/100 SDRAM
HM5225405BLTT-75 制造商:ELPIDA 制造商全稱:Elpida Memory 功能描述:256M LVTTL interface SDRAM 133 MHz/100 MHz 4-Mword 】 16-bit 】 4-bank/8-Mword 】 8-bit 】 4-bank /16-Mword 】 4-bit 】 4-bank PC/133, PC/100 SDRAM
HM5225405BLTT-A6 制造商:ELPIDA 制造商全稱:Elpida Memory 功能描述:256M LVTTL interface SDRAM 133 MHz/100 MHz 4-Mword 】 16-bit 】 4-bank/8-Mword 】 8-bit 】 4-bank /16-Mword 】 4-bit 】 4-bank PC/133, PC/100 SDRAM