參數(shù)資料
型號: μPD45256163
廠商: NEC Corp.
英文描述: 256M-Bit Synchronous DRAM(256M 同步 動態(tài)RAM)
中文描述: 256M位同步DRAM(256M同步動態(tài)RAM)的
文件頁數(shù): 25/84頁
文件大?。?/td> 1052K
代理商: ΜPD45256163
25
μ
PD45256441,45256841,45256163
Preliminary Data Sheet
9. Precharge
The precharge command can be issued anytime after t
RAS(MIN.)
is satisfied.
Soon after the precharge command is issued, precharge operation performed and the synchronous DRAM enters
the idle state after t
RP
is satisfied. The parameter t
RP
is the time required to perform the precharge.
The earliest timing in a read cycle that a precharge command can be issued without losing any data in the burst
is as follows.
It is depending on the /CAS latency and clock cycle time.
T0
T1
T2
T3
T4
T5
T6
T7
Burst length=4
Read
Read
Q1
Q2
Q3
Q4
PRE
Hi-Z
Q1
Q2
Q3
Q4
PRE
Hi-Z
(t
RAS
must be satisfied)
CLK
Command
/CAS latency = 2
DQ
Command
/CAS latency = 3
DQ
T8
In order to write all data to the memory cell correctly, the asynchronous parameter “t
DPL
” must be satisfied. The
t
DPL(MIN.)
specification defines the earliest time that a precharge command can be issued. Minimum number of
clocks is calculated by dividing t
DPL (MIN.)
with clock cycle time.
In summary, the precharge command can be issued relative to reference clock that indicates the last data word is
valid. In the following table, minus means clocks before the reference; plus means time after the reference
/CAS latency
Read
Write
2
–1
+t
DPL(MIN.)
3
–2
+t
DPL(MIN.)
相關PDF資料
PDF描述
μPD45256441 256M-Bit Synchronous DRAM(256M 同步 動態(tài)RAM)
μPD45256841 256M-Bit Synchronous DRAM(256M 同步 動態(tài)RAM)
μPD4564163 64M-bit Synchronous DRAM(64M同步動態(tài)RAM)
μPD4564441 64M-bit Synchronous DRAM(64M同步動態(tài)RAM)
μPD4564841 64M-bit Synchronous DRAM(64M同步動態(tài)RAM)
相關代理商/技術參數(shù)
參數(shù)描述
PD4558C 制造商:Panasonic Industrial Company 功能描述:IC
PD-45A 功能描述:線性和開關式電源 40W 5V/3.2A 12V/2A RoHS:否 制造商:TDK-Lambda 產品:Switching Supplies 開放式框架/封閉式:Enclosed 輸出功率額定值:800 W 輸入電壓:85 VAC to 265 VAC 輸出端數(shù)量:1 輸出電壓(通道 1):20 V 輸出電流(通道 1):40 A 商用/醫(yī)用: 輸出電壓(通道 2): 輸出電流(通道 2): 安裝風格:Rack 長度: 寬度: 高度:
PD-45B 功能描述:線性和開關式電源 44.8W 5V/3.2A 24V/1.2A RoHS:否 制造商:TDK-Lambda 產品:Switching Supplies 開放式框架/封閉式:Enclosed 輸出功率額定值:800 W 輸入電壓:85 VAC to 265 VAC 輸出端數(shù)量:1 輸出電壓(通道 1):20 V 輸出電流(通道 1):40 A 商用/醫(yī)用: 輸出電壓(通道 2): 輸出電流(通道 2): 安裝風格:Rack 長度: 寬度: 高度:
PD45VN6C100 制造商:Banner Engineering 功能描述:SENSOR, PHOTOELECTRIC, PICODOT, CONVERGENT LASER, FOCAL POINT, 1
PD45VN6C100Q 制造商:Banner Engineering 功能描述:Sensor, PicoDot, Convergent Laser, Focal Point: 102mm, Input 10-30VDC, Cable 2m