CY7C1354BV25-200AC Cypress Semiconductor Corp, CY7C1354BV25-200AC Datasheet - Page 7

• Manufacturer Part Number: CY7C1354BV25-200AC
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C1354BV25-200AC

• Lead Free Status / Rohs Status: Not Compliant

Document #: 38-05292 Rev. *E
Pin Definitions
Functional Overview
The
synchronous-pipelined Burst NoBL SRAMs designed specifi-
cally to eliminate wait states during Write/Read transitions. All
synchronous inputs pass through input registers controlled by
the rising edge of the clock. The clock signal is qualified with
the Clock Enable input signal (CEN). If CEN is HIGH, the clock
signal is not recognized and all internal states are maintained.
All synchronous operations are qualified with CEN. All data
outputs pass through output registers controlled by the rising
edge of the clock. Maximum access delay from the clock rise
(t
Accesses can be initiated by asserting all three Chip Enables
(CE
Enable (CEN) is active LOW and ADV/LD is asserted LOW,
the address presented to the device will be latched. The
access can either be a read or write operation, depending on
the status of the Write Enable (WE). BW
conduct byte write operations.
Write operations are qualified by the Write Enable (WE). All
writes are simplified with on-chip synchronous self-timed write
circuitry.
Three synchronous Chip Enables (CE
asynchronous Output Enable (OE) simplify depth expansion.
All operations (Reads, Writes, and Deselects) are pipelined.
ADV/LD should be driven LOW once the device has been
deselected in order to load a new address for the next
operation.
Single Read Accesses
A read access is initiated when the following conditions are
satisfied at clock rise: (1) CEN is asserted LOW, (2) CE
and CE
signal WE is deasserted HIGH, and (4) ADV/LD is asserted
LOW. The address presented to the address inputs is latched
into the Address Register and presented to the memory core
and control logic. The control logic determines that a read
access is in progress and allows the requested data to
propagate to the input of the output register. At the rising edge
of the next clock the requested data is allowed to propagate
through the output register and onto the data bus within 3.2 ns
(200-MHz device) provided OE is active LOW. After the first
clock of the read access the output buffers are controlled by
OE and the internal control logic. OE must be driven LOW in
order for the device to drive out the requested data. During the
second clock, a subsequent operation (Read/Write/Deselect)
can be initiated. Deselecting the device is also pipelined.
Therefore, when the SRAM is deselected at clock rise by one
of the chip enable signals, its output will three-state following
the next clock rise.
V
NC
E(18,36,72, 144, 288)
ZZ
CO
SS
1
) is 3.2 ns (200-MHz device).
, CE
Pin Name
3
CY7C1354BV25
2
are ALL asserted active, (3) the Write Enable input
, CE
3
) active at the rising edge of the clock. If Clock
(continued)
Asynchronous
I/O Type
Ground
Input-
and
–
–
CY7C1356BV25
1
, CE
Ground for the device. Should be connected to ground of the system.
No connects. This pin is not connected to the die.
These pins are not connected. They will be used for expansion to the 18M, 36M,
72M, 144M and 288M densities.
ZZ “sleep” Input. This active HIGH input places the device in a non-time critical “sleep”
condition with data integrity preserved. During normal operation, this pin can be
connected to Vss or left floating.
[d:a]
2
can be used to
, CE
3
) and an
1
, CE
are
2
,
Burst Read Accesses
The CY7C1354BV25 and CY7C1356BV25 have an on-chip
burst counter that allows the user the ability to supply a single
address and conduct up to four Reads without reasserting the
address inputs. ADV/LD must be driven LOW in order to load
a new address into the SRAM, as described in the Single Read
Access section above. The sequence of the burst counter is
determined by the MODE input signal. A LOW input on MODE
selects a linear burst mode, a HIGH selects an interleaved
burst sequence. Both burst counters use A0 and A1 in the
burst sequence, and will wrap-around when incremented suffi-
ciently. A HIGH input on ADV/LD will increment the internal
burst counter regardless of the state of chip enables inputs or
WE. WE is latched at the beginning of a burst cycle. Therefore,
the type of access (Read or Write) is maintained throughout
the burst sequence.
Single Write Accesses
Write access are initiated when the following conditions are
satisfied at clock rise: (1) CEN is asserted LOW, (2) CE
and CE
is asserted LOW. The address presented to A
into the Address Register. The write signals are latched into
the Control Logic block.
On the subsequent clock rise the data lines are automatically
three-stated regardless of the state of the OE input signal. This
allows the external logic to present the data on DQ and DQP
(DQ
for CY7C1356BV25). In addition, the address for the subse-
quent access (Read/Write/Deselect) is latched into the
Address Register (provided the appropriate control signals are
asserted).
On the next clock rise the data presented to DQ and DQP
(DQ
CY7C1356BV25) (or a subset for byte write operations, see
Write Cycle Description table for details) inputs is latched into
the device and the write is complete.
The data written during the Write operation is controlled by BW
(BW
signals. The CY7C1354BV25/ CY7C1356BV25 provides byte
write capability that is described in the Write Cycle Description
table. Asserting the Write Enable input (WE) with the selected
Byte Write Select (BW) input will selectively write to only the
desired bytes. Bytes not selected during a byte write operation
will remain unaltered. A synchronous self-timed write
mechanism has been provided to simplify the write operations.
Byte write capability has been included in order to greatly
simplify Read/Modify/Write sequences, which can be reduced
to simple byte write operations.
a,b,c,d
a,b,c,d
a,b,c,d
3
are ALL asserted active, and (3) the write signal WE
/DQP
/DQP
Pin Description
for CY7C1354BV25 and BW
a,b,c,d
a,b,c,d
for CY7C1354BV25 & DQ
for CY7C1354BV25 and DQ
CY7C1354BV25
CY7C1356BV25
a,b
for CY7C1356BV25)
0
–A
a,b
Page 7 of 27
16
/DQP
a,b
is loaded
/DQP
1
, CE
a,b
for
a,b
2
,