CY7C1643KV18/CY7C1645KV18
144-Mbit QDR® II+ SRAM Four-Word
Burst Architecture (2.0 Cycle Read Latency)
144-Mbit QDR® II+ SRAM Four-Word Burst Architecture (2.0 Cycle Read Latency)
Features
■ Separate independent read and write data ports
❐ Supports concurrent transactions
■ 450-MHz clock for high bandwidth
■ Four-word burst for reducing address bus frequency
■ Double data rate (DDR) interfaces on both read and write ports
(data transferred at 900 MHz) at 450 MHz
■ Available in 2.0-clock cycle latency
■ Two input clocks (K and K) for precise DDR timing
❐ SRAM uses rising edges only
■ Echo clocks (CQ and CQ) simplify data capture in high-speed
systems
■ Data valid pin (QVLD) to indicate valid data on the output
■ Single multiplexed address input bus latches address inputs
for read and write ports
■ Separate port selects for depth expansion
■ Synchronous internally self-timed writes
■ Quad data rate (QDR®) II+ operates with 2.0-cycle read latency
when DOFF is asserted high
■ Operates similar to QDR I device with one cycle read latency
when DOFF is asserted low
■ Available in × 18, and × 36 configurations
■ Full data coherency, providing most current data
■ Core VDD = 1.8 V ± 0.1 V; I/O VDDQ = 1.4 V to VDD [1]
❐ Supports both 1.5-V and 1.8-V I/O supply
■ High-speed transceiver logic (HSTL) Inputs and variable drive
HSTL output buffers
■ Available in 165-ball fine pitch ball grid array (FBGA) package
(15 × 17 × 1.4 mm)
■ Offered in both Pb-free and non Pb-free packages
■ JTAG 1149.1 compatible test access port
■ Phase locked loop (PLL) for accurate data placement
Configurations
With Read Cycle Latency of 2.0 cycles:
CY7C1643KV18 – 8M × 18
CY7C1645KV18 – 4M × 36
Functional Description
The CY7C1643KV18, and CY7C1645KV18 are 1.8-V
synchronous pipelined SRAMs, equipped with QDR II+
architecture. Similar to QDR II architecture, QDR II+ architecture
consists of two separate ports: the read port and the write port to
access the memory array. The read port has dedicated data
outputs to support read operations and the write port has
dedicated data inputs to support write operations. QDR II+
architecture has separate data inputs and data outputs to
completely eliminate the need to “turnaround” the data bus that
exists with common I/O devices. Each port is accessed through
a common address bus. Addresses for read and write addresses
are latched on alternate rising edges of the input (K) clock.
Accesses to the QDR II+ read and write ports are completely
independent of one another. To maximize data throughput, both
read and write ports are equipped with DDR interfaces. Each
address location is associated with four 18-bit words
(CY7C1643KV18), or 36-bit words (CY7C1645KV18) that burst
sequentially into or out of the device. Because data is transferred
into and out of the device on every rising edge of both input
clocks (K and K), memory bandwidth is maximized while
simplifying system design by eliminating bus “turnarounds”.
Depth expansion is accomplished with port selects, which
enables each port to operate independently.
All synchronous inputs pass through input registers controlled by
the K or K input clocks. All data outputs pass through output
registers controlled by the K or K input clocks. Writes are
conducted with on-chip synchronous self-timed write circuitry.
For a complete list of related documentation, click here.
Selection Guide
Maximum operating frequency
Maximum operating current
Description
× 18
× 36
450 MHz
450
940
1290
400 MHz
400
860
1170
Unit
MHz
mA
Note
1. The Cypress QDR II+ devices surpass the QDR consortium specification and can support VDDQ = 1.4 V to VDD.
Cypress Semiconductor Corporation • 198 Champion Court
Document Number: 001-44059 Rev. *M
• San Jose, CA 95134-1709 • 408-943-2600
Revised November 15, 2016
