參數(shù)資料
型號: CY7C1318AV18
廠商: Cypress Semiconductor Corp.
英文描述: 18-Mbit DDR-II SRAM 2-Word Burst Architecture(18-Mb DDR-II SRAM(2-Word Burst結(jié)構(gòu)))
中文描述: 18兆位的DDR - II SRAM的2字突發(fā)架構(gòu)(18 - MB的的DDR - II SRAM的(2字突發(fā)結(jié)構(gòu)))
文件頁數(shù): 7/20頁
文件大?。?/td> 228K
代理商: CY7C1318AV18
CY7C1316AV18
CY7C1318AV18
CY7C1320AV18
Document #: 38-05499 Rev. *B
Page 7 of 20
Programmable Impedance
An external resistor, RQ, must be connected between the ZQ
pin on the SRAM and V
SS
to allow the SRAM to adjust its
output driver impedance. The value of RQ must be 5x the
value of the intended line impedance driven by the SRAM, The
allowable range of RQ to guarantee impedance matching with
a tolerance of ±15% is between 175
and 350
,
with
V
DDQ
= 1.5V. The output impedance is adjusted every 1024
cycles upon power-up to account for drifts in supply voltage
and temperature.
Echo Clocks
Echo clocks are provided on the DDR-II to simplify data
capture on high-speed systems. Two echo clocks are
generated by the DDR-II. CQ is referenced with respect to C
and CQ is referenced with respect to C. These are
free-running clocks and are synchronized to the output clock
of the DDR-II. In the single clock mode, CQ is generated with
respect to K and CQ is generated with respect to K. The
timings for the echo clocks are shown in the AC Timing table.
DLL
These chips utilize a Delay Lock Loop (DLL) that is designed
to function between 80 MHz and the specified maximum clock
frequency. The DLL may be disabled by applying ground to the
DOFF pin. The DLL can also be reset by slowing the cycle time
of input clocks K and K to greater than 30 ns.
Notes:
1. The above application shows two DDR-II used.
2. X = “Don’t Care,” H = Logic HIGH, L = Logic LOW,
represents rising edge.
3. Device will power-up deselected and the outputs in a three-state condition.
4. On CY7C1318AV18 and CY7C1320AV18, A” represents address location latched by the devices when transaction was initiated and A2 represents the addresses
sequence in the burst. On CY7C1316AV18, A1 represents A +‘0’ and A2 represents A +‘1.’
5. “t” represents the cycle at which a Read/Write operation is started. t+1 and t + 2 are the first and second clock cycles succeeding the “t” clock cycle.
6. Data inputs are registered at K and K rising edges. Data outputs are delivered on C and C rising edges, except when in single clock mode.
7. It is recommended that K = K and C = C = HIGH when clock is stopped. This is not essential, but permits most rapid restart by overcoming transmission line
charging symmetrically.
Application Example
[1]
Truth Table
[2, 3, 4, 5, 6, 7]
Operation
K
LD
L
R/W
L
DQ
DQ
Write Cycle:
Load address; wait one cycle; input write data on consecutive K
and K rising edges.
Read Cycle:
Load address; wait one and a half cycle; read data on consec-
utive C and C rising edges.
NOP: No Operation
Standby: Clock Stopped
L-H
D(A1)at K(t + 1)
D(A2) at K(t + 1)
L-H
L
H
Q(A1) at C(t + 1)
Q(A2) at C(t + 2)
L-H
H
X
X
X
High-Z
Previous State
High-Z
Previous State
Stopped
LD#
Vterm = 0.75V
Vterm = 0.75V
C C#
R/W#
ZQ
CQ/CQ#
K#
DQ
A
LD#
C C#
R/W#
ZQ
CQ/CQ#
K#
DQ
A
BUS
MASTER
(CPU
or
ASIC)
SRAM#1
SRAM#2
DQ
Addresses
Cycle Start#
R/W#
Return CLK
Source CLK
Return CLK#
Source CLK#
Echo Clock1/Echo Clock#1
Echo Clock2/Echo Clock#2
R = 50
ohms
R = 250
ohms
R
= 250ohms
Burst Address Table
(CY7C1318AV18,
CY7C1320AV18)
First Address (External)
X..X0
X..X1
Second Address (Internal)
X..X1
X..X0
相關(guān)PDF資料
PDF描述
CY7C1316AV18 18-Mbit DDR-II SRAM 2-Word Burst Architecture
CY7C1316AV18-167BZC 18-Mbit DDR-II SRAM 2-Word Burst Architecture
CY7C1318AV18-200BZC 18-Mbit DDR-II SRAM 2-Word Burst Architecture
CY7C1318AV18-250BZC 18-Mbit DDR-II SRAM 2-Word Burst Architecture
CY7C1320AV18-167BZC 18-Mbit DDR-II SRAM 2-Word Burst Architecture
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
CY7C1318AV18-167BZC 制造商:Cypress Semiconductor 功能描述: 制造商:Rochester Electronics LLC 功能描述:
CY7C1318AV-200BZCES 制造商:Cypress Semiconductor 功能描述:
CY7C1318BV18-167BZC 功能描述:靜態(tài)隨機(jī)存取存儲器 1Mx18 1.8V COM DDR II 靜態(tài)隨機(jī)存取存儲器 RoHS:否 制造商:Cypress Semiconductor 存儲容量:16 Mbit 組織:1 M x 16 訪問時間:55 ns 電源電壓-最大:3.6 V 電源電壓-最小:2.2 V 最大工作電流:22 uA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSOP-48 封裝:Tray
CY7C1318BV18-200BZI 功能描述:靜態(tài)隨機(jī)存取存儲器 1Mx18 1.8V IND DDR II 靜態(tài)隨機(jī)存取存儲器 RoHS:否 制造商:Cypress Semiconductor 存儲容量:16 Mbit 組織:1 M x 16 訪問時間:55 ns 電源電壓-最大:3.6 V 電源電壓-最小:2.2 V 最大工作電流:22 uA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSOP-48 封裝:Tray
CY7C1318BV18-250BZC 功能描述:靜態(tài)隨機(jī)存取存儲器 1Mx18 1.8V COM DDR II 靜態(tài)隨機(jī)存取存儲器 RoHS:否 制造商:Cypress Semiconductor 存儲容量:16 Mbit 組織:1 M x 16 訪問時間:55 ns 電源電壓-最大:3.6 V 電源電壓-最小:2.2 V 最大工作電流:22 uA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSOP-48 封裝:Tray