CY7C1546KV18 Datasheet, PDF (1/31 Pages) Cypress Semiconductor – 72-Mbit DDR II+ SRAM 2-Word Burst Architecture (2.0 Cycle Read Latency)

CY7C1546KV18, CY7C1557KV18
CY7C1548KV18, CY7C1550KV18
72-Mbit DDR II+ SRAM 2-Word Burst
Architecture (2.0 Cycle Read Latency)
72-Mbit DDR II+ SRAM 2-Word Burst Architecture (2.0 Cycle Read Latency)
Features
■ 72-Mbit density (8 M × 8, 8 M × 9, 4 M × 18, 2 M × 36)
■ 450-MHz clock for high bandwidth
■ 2-word burst for reducing address bus frequency
■ Double data rate (DDR) interfaces
(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
■ Synchronous internally self-timed writes
■ DDR II+ operates with 2.0 cycle read latency when DOFF is
asserted HIGH
■ Operates similar to DDR I device with 1 cycle read latency when
DOFF is asserted LOW
■ Core V_DD = 1.8 V ± 0.1 V; I/O V_DDQ = 1.4 V to V_DD[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
(13 × 15 × 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:
CY7C1546KV18 – 8 M × 8
CY7C1557KV18 – 8 M × 9
CY7C1548KV18 – 4 M × 18
CY7C1550KV18 – 2 M × 36
Functional Description
The CY7C1546KV18, CY7C1557KV18, CY7C1548KV18, and
CY7C1550KV18 are 1.8 V Synchronous Pipelined SRAMs
equipped with DDR II+ architecture. The DDR II+ consists of an
SRAM core with advanced synchronous peripheral circuitry.
Addresses for read and write are latched on alternate rising
edges of the input (K) clock. Write data is registered on the rising
edges of both K and K. Read data is driven on the rising edges
of K and K. Each address location is associated with two 8-bit
words (CY7C1546KV18), 9-bit words (CY7C1557KV18), 18-bit
words (CY7C1548KV18), or 36-bit words (CY7C1550KV18) that
burst sequentially into or out of the device.
Asynchronous inputs include an output impedance matching
input (ZQ). Synchronous data outputs (Q, sharing the same
physical pins as the data inputs D) are tightly matched to the two
output echo clocks CQ/CQ, eliminating the need for separately
capturing data from each individual DDR SRAM in the system
design.
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.
Note
1. The Cypress QDR II+ devices surpass the QDR consortium specification and can support V_DDQ = 1.4 V to V_DD.
Cypress Semiconductor Corporation • 198 Champion Court
Document Number: 001-15879 Rev. *I
• San Jose, CA 95134-1709 • 408-943-2600
Revised January 25, 2011
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