PRELIMINARY
CY7C1416AV18
CY7C1427AV18
CY7C1418AV18
CY7C1420AV18
Document Number: 38-05616 Rev. **
Page 9 of 24
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 CY7C1418AV18 and CY7C1420AV18, “A1” represents address location latched by the devices when transaction was initiated and A2 represents the addresses
sequence in the burst. On CY7C1416AV18, “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]
LD#
Vterm = 0.75V
Vterm = 0.75V
CC#
R/W#
ZQ
CQ/CQ#
K#
DQ
A
K
LD#
C C#
R/W#
ZQ
CQ/CQ#
K#
DQ
A
K
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 = 50ohms
R = 250ohms
R = 250ohms
Truth Table[2, 3, 4, 5, 6, 7]
Operation
K
LD
R/W
DQ
DQ
Write Cycle:
Load address; wait one cycle; input write data on consecutive K
and K rising edges.
L-H
L
L
D(A1)at K(t + 1)
↑ D(A2) at K(t + 1) ↑
Read Cycle:
Load address; wait one and a half cycle; read data on consec-
utive C and C rising edges.
L-H
L
H
Q(A1) at C(t + 1)
↑ Q(A2) at C(t + 2) ↑
NOP: No Operation
L-H
H
X
High-Z
High-Z
Standby: Clock Stopped
Stopped
X
X
Previous State
Previous State
Burst Address Table (CY7C1418AV18, CY7C1420AV18)
First Address (External)
Second Address (Internal)
X..X0
X..X1
X..X1
X..X0