CY7C1392BV18 Datasheet, PDF (6/27 Pages) Cypress Semiconductor – 18-Mbit DDR-II SIO SRAM 2-Word Burst Architecture

CY7C1392BV18
CY7C1992BV18
CY7C1393BV18
CY7C1394BV18
Pin Definitions
Pin Name
D_[x:0]
LD
NWS_[1:0]
BWS_[3:0]
A
Q_[x:0]
R/W
C
C
K
K
CQ
I/O
Pin Description
Input-
Synchronous
Input-
Synchronous
Data Input signals, sampled on the rising edge of K and K clocks during valid Write opera-
tions.
CY7C1392BV18 − D_[7:0]
CY7C1992BV18 − D_[8:0]
CY7C1393BV18 − D_[17:0]
CY7C1394BV18 − D_[35:0]
Synchronous Load: This input is brought LOW when a bus cycle sequence is to be defined. This
definition includes address and Read/Write direction. All transactions operate on a burst of 2 data
(one period of bus activity).
Input-
Synchronous
Nibble Write Select 0, 1 − active LOW (CY7C1392BV18 only). Sampled on the rising edge of
the K and K clocks during Write operations. Used to select which nibble is written into the device
during the current portion of the Write operations. Nibbles not written remain unaltered.
NWS₀ controls D_[3:0] and NWS₁ controls D_[7:4].
All the Nibble Write Selects are sampled on the same edge as the data. Deselecting a Nibble Write
Select will cause the corresponding nibble of data to be ignored and not written into the device.
Input-
Synchronous
Byte Write Select 0, 1, 2, and 3 − active LOW. Sampled on the rising edge of the K and K clocks
during Write operations. Used to select which byte is written into the device during the current
portion of the Write operations. Bytes not written remain unaltered.
CY7C1992BV18 − BWS₀ controls D_[8:0].
CY7C1393BV18 − BWS₀ controls D_[8:0] and BWS₁ controls D_[17:9].
CY7C1394BV18 − BWS₀ controls D_[8:0], BWS₁ controls D_[17:9], BWS₂ controls D_[26:18] and BWS₃
controls D_[35:27]
All the Byte Write Selects are sampled on the same edge as the data. Deselecting a Byte Write
Select will cause the corresponding byte of data to be ignored and not written into the device.
Input-
Synchronous
Address Inputs. Sampled on the rising edge of the K clock during active Read and Write opera-
tions. These address inputs are multiplexed for both Read and Write operations. Internally, the
device is organized as 2M x 8 (2 arrays each of 1M x 8) for CY7C1392BV18, 2M x 9 (2 arrays
each of 1M x 9) for CY7C1992BV18, 1M x 18 (two arrays each of 512K x 18) for CY7C1393BV18
and 1M x 36 (2 arrays each of 128K x 36) for CY7C1394BV18. Therefore only 20 address inputs
are needed to access the entire memory array of CY7C1392BV18 and CY7C1992BV18, 19
address inputs for CY7C1393BV18, and 18 address inputs for CY7C1394BV18. These inputs are
ignored when the appropriate port is deselected.
Output-
Synchronous
Input-
Synchronous
Data Output signals. These pins drive out the requested data during a Read operation. Valid
data is driven out on the rising edge of both the C and C clocks during Read operations or K and
K when in single clock mode. When Read access is deselected, Q_[x:0] are automatically tri-stated.
CY7C1392BV18 − Q_[7:0]
CY7C1393BV18 − Q_[17:0]
CY7C1394BV18 − Q_[35:0]
Synchronous Read/Write Input: When LD is LOW, this input designates the access type (Read
when R/W is HIGH, Write when R/W is LOW) for loaded address. R/W must meet the set-up and
hold times around edge of K.
Input-
Clock
Positive Input Clock for Output Data. C is used in conjunction with C to clock out the Read data
from the device. C and C can be used together to deskew the flight times of various devices on
the board back to the controller. See application example for further details.
Input-
Clock
Negative Input Clock for Output Data. C is used in conjunction with C to clock out the Read
data from the device. C and C can be used together to deskew the flight times of various devices
on the board back to the controller. See application example for further details.
Input-
Clock
Positive Input Clock Input. The rising edge of K is used to capture synchronous inputs to the
device and to drive out data through Q_[x:0] when in single clock mode. All accesses are initiated
on the rising edge of K.
Input-
Clock
Echo Clock
Negative Input Clock Input. K is used to capture synchronous inputs being presented to the
device and to drive out data through Q_[x:0] when in single clock mode.
CQ is referenced with respect to C. This is a free-running clock and is synchronized to the input
clock for output data (C) of the DDR-II. In the single clock mode, CQ is generated with respect to
K. The timings for the echo clocks are shown in the AC Timing table.
Document Number: 38-05623 Rev. *C
Page 6 of 27
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