CY7C1548KV18_12 Datasheet, PDF (1/29 Pages) Cypress Semiconductor – 72-Mbit DDR II+ SRAM Two-Word Burst Architecture (2.0 Cycle Read Latency)

CY7C1548KV18, CY7C1550KV18
72-Mbit DDR II+ SRAM Two-Word Burst
Architecture (2.0 Cycle Read Latency)
72-Mbit DDR II+ SRAM Two-Word Burst Architecture (2.0 Cycle Read Latency)
Features
■ 72-Mbit density (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:
CY7C1548KV18 – 4 M × 18
CY7C1550KV18 – 2 M × 36
Functional Description
The 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 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.
Selection Guide
Maximum operating frequency
Maximum operating current
Description
450 MHz 400 MHz Unit
450
400
MHz
× 18
650
590
mA
× 36
820
750
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. *K
• San Jose, CA 95134-1709 • 408-943-2600
Revised June 26, 2012