CY7C1512V18-250BZC Cypress Semiconductor Corp, CY7C1512V18-250BZC Datasheet - Page 8

• Manufacturer Part Number: CY7C1512V18-250BZC
• Description: IC SRAM 72MBIT 250MHZ 165TFBGA
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C1512V18-250BZC

• Format - Memory: RAM
• Memory Type: SRAM - Synchronous, QDR II
• Memory Size: 72M (4M x 18)
• Speed: 250MHz
• Interface: Parallel
• Voltage - Supply: 1.7 V ~ 1.9 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 165-TFBGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Functional Overview
The CY7C1510V18, CY7C1525V18, CY7C1512V18, and
CY7C1514V18 are synchronous pipelined Burst SRAMs with a
read port and a write port. The read port is dedicated to read
operations and the write port is dedicated to write operations.
Data flows into the SRAM through the write port and flows out
through the read port. These devices multiplex the address
inputs to minimize the number of address pins required. By
having separate read and write ports, the QDR-II completely
eliminates the need to turn-around the data bus and avoids any
possible data contention, thereby simplifying system design.
Each access consists of two 8-bit data transfers in the case of
CY7C1510V18, two 9-bit data transfers in the case of
CY7C1525V18, two 18-bit data transfers in the case of
CY7C1512V18, and two 36-bit data transfers in the case of
CY7C1514V18 in one clock cycle.
Accesses for both ports are initiated on the rising edge of the
positive input clock (K). All synchronous input timing is refer-
enced from the rising edge of the input clocks (K and K) and all
output timing is referenced to the output clocks (C and C, or K
and K when in single clock mode).
All synchronous data inputs (D
controlled by the input clocks (K and K). All synchronous data
outputs (Q
rising edge of the output clocks (C and C, or K and K when in
single clock mode).
All synchronous control (RPS, WPS, BWS
through input registers controlled by the rising edge of the input
clocks (K and K).
CY7C1512V18 is described in the following sections. The same
basic descriptions apply to CY7C1510V18, CY7C1525V18, and
CY7C1514V18.
Read Operations
The CY7C1512V18 is organized internally as two arrays of 2M x
18. Accesses are completed in a burst of two sequential 18-bit
data words. Read operations are initiated by asserting RPS
active at the rising edge of the positive input clock (K). The
address is latched on the rising edge of the K clock. The address
presented to the address inputs is stored in the read address
register. Following the next K clock rise, the corresponding
lowest order 18-bit word of data is driven onto the Q
C as the output timing reference. On the subsequent rising edge
of C, the next 18-bit data word is driven onto the Q
requested data is valid 0.45 ns from the rising edge of the output
clock (C and C or K and K when in single clock mode).
Synchronous internal circuitry automatically tri-states the outputs
following the next rising edge of the output clocks (C/C). This
enables for a seamless transition between devices without the
insertion of wait states in a depth expanded memory.
Write Operations
Write operations are initiated by asserting WPS active at the
rising edge of the positive input clock (K). On the same K clock
rise the data presented to D
lower 18-bit write data register, provided BWS
asserted active. On the subsequent rising edge of the negative
input clock (K), the address is latched and the information
Document #: 38-05489 Rev. *F
[x:0]
) pass through output registers controlled by the
[17:0]
[x:0]
is latched and stored into the
) pass through input registers
[x:0]
) inputs pass
[1:0]
[17:0]
[17:0]
are both
using
. The
presented to D
provided BWS
are then written into the memory array at the specified location.
When deselected, the write port ignores all inputs after the
pending write operations have been completed.
Byte Write Operations
Byte write operations are supported by the CY7C1512V18. A
write operation is initiated as described in the
section. The bytes that are written are determined by BWS
BWS
Asserting the appropriate Byte Write Select input during the data
portion of a write latches the data being presented and writes it
into the device. Deasserting the Byte write select input during the
data portion of a write enables the data stored in the device for
that byte to remain unaltered. This feature can be used to
simplify read, modify, or write operations to a byte write
operation.
Single Clock Mode
The CY7C1510V18 can be used with a single clock that controls
both the input and output registers. In this mode the device
recognizes only a single pair of input clocks (K and K) that control
both the input and output registers. This operation is identical to
the operation if the device had zero skew between the K/K and
C/C clocks. All timing parameters remain the same in this mode.
To use this mode of operation, the user must tie C and C HIGH
at power on. This function is a strap option and not alterable
during device operation.
Concurrent Transactions
The read and write ports on the CY7C1512V18 operate
completely independently of one another. As each port latches
the address inputs on different clock edges, the user can read or
write to any location, regardless of the transaction on the other
port. The user can start reads and writes in the same clock cycle.
If the ports access the same location at the same time, the SRAM
delivers the most recent information associated with the
specified address location. This includes forwarding data from a
write cycle that was initiated on the previous K clock rise.
Depth Expansion
The CY7C1512V18 has a port select input for each port. This
enables for easy depth expansion. Both port selects are sampled
on the rising edge of the positive input clock only (K). Each port
select input can deselect the specified port. Deselecting a port
does not affect the other port. All pending transactions (read and
write) are completed before the device is deselected.
Programmable Impedance
An external resistor, RQ, must be connected between the ZQ pin
on the SRAM and V
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 175Ω and 350Ω
output impedance is adjusted every 1024 cycles upon power up
to account for drifts in supply voltage and temperature.
1
, which are sampled with each set of 18-bit data words.
CY7C1510V18, CY7C1525V18
CY7C1512V18, CY7C1514V18
[1:0]
[17:0]
are both asserted active. The 36 bits of data
SS
is also stored into the write data register,
to enable the SRAM to adjust its output
,
with V
Write Operations
DDQ
Page 8 of 29
= 1.5V. The
0
and
[+] Feedback