CY7C1511V18, CY7C1526V18
CY7C1513V18, CY7C1515V18
Document Number: 38-05363 Rev. *F Page 10 of 32
Application Example
Figure 1 shows four QDR-II used in an application.
Figure 1. Application Example
Truth Table
The truth table for CY7C1511V18, CY7C1526V18, CY7C1513V18, and CY7C1515V18 follows. [2, 3, 4, 5, 6, 7]
Operation KRPS WPS DQ DQ DQ DQ
Write Cycle:
Load address on the rising
edge of K; input write data
on two consecutive K and
K rising edges.
L-H H [8] L [9] D(A) at K(t + 1)↑D(A + 1) at K(t + 1)↑D(A + 2) at K(t + 2)↑D(A + 3) at K(t + 2)↑
Read Cycle:
Load address on the rising
edge of K; wait one and a
half cycle; read data on
two consecutive C and C
rising edges.
L-H L [9] XQ(A) at C(t + 1)↑Q(A + 1) at C(t + 2)↑Q(A + 2) at C(t + 2)↑Q(A + 3) at C(t + 3)↑
NOP: No Operation L-H H H D = X
Q = High-Z D = X
Q = High-Z D = X
Q = High-Z D = X
Q = High-Z
Standby: Clock Stopped Stopped X X Previous State Previous State Previous State Previous State
R = 250ohms
Vt
R
R = 250ohms
Vt
Vt
R
Vt = Vddq/2
R = 50ohms
R
CC#
D
A

SRAM #4

R
P
S
#
W
P
S
#
B
W
S
#K
ZQ
CQ/CQ#
Q
K#
CC#
D
AK

SRAM #1

R
P
S
#
W
P
S
#
B
W
S
#
ZQ
CQ/CQ#
Q
K#

BUS

MASTER

(CPU

or

ASIC)

DATA IN
DATA OUT
Address
RPS#
WPS#
BWS#
Source K
Source K#
Delayed K
Delayed K#
CLKIN/CLKIN#
Notes
2. X = “Don't Care,” H = Logic HIGH, L = Logic LOW, ↑represents rising edge.
3. Device powers up deselected with the outputs in a tri-state condition.
4. “A” represents address location latched by the devices when transaction was initiated. A + 1, A + 2, and A +3 represents the address sequence in the burst.
5. “t” represents the cycle at which a read/write operation is started. t + 1, t + 2, and t + 3 are the first, second and third clock cycles respectively 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.
8. If this signal was LOW to initiate the previous cycle, this signal becomes a “Don’t Care” for this operation.
9. This signal was HIGH on previous K clock rise. Initiating consecutive read or write operations on consecutive K clock rises is not permitted. The device ignores the
second read or write request.
[+] Feedback