CY7C1546V18
CY7C1557V18
CY7C1548V18
CY7C1550V18
72-Mbit DDR-II+ SRAM 2-Word Burst
Architecture (2.0 Cycle Read Latency)
Features
Functional Description
■ 72-Mbit density (8M x 8, 8M x 9, 4M x 18, 2M x 36)
■ 300 MHz to 375 MHz clock for high bandwidth
■ 2-Word burst for reducing address bus frequency
The CY7C1546V18, CY7C1557V18, CY7C1548V18, and
CY7C1550V18 are 1.8V Synchronous Pipelined SRAM
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 both K and K. Each address location is associated with two
8-bit words (CY7C1546V18), 9-bit words (CY7C1557V18),
18-bit words (CY7C1548V18), or 36-bit words (CY7C1550V18)
that burst sequentially into or out of the device.
■ Double Data Rate (DDR) interfaces
(data transferred at 750 MHz) at 375 MHz
■ Read latency of 2.0 clock cycles
■ Two input clocks (K and K) for precise DDR timing
❐ SRAM uses rising edges only
Asynchronous inputs include output impedance matching input
■ Echo clocks (CQ and CQ) simplify data capture in high speed
systems
(ZQ). Synchronous data outputs (Q, that share the same
physical pins with the data inputs, D) are tightly matched to the
two output echo clocks CQ/CQ, eliminating the need to capture
data separately from individual DDR SRAMs in the system
design.
■ Data valid pin (QVLD) to indicate valid data on the output
■ Synchronous internally self-timed writes
[1]
■ Core VDD = 1.8V ± 0.1V; IO VDDQ = 1.4V to VDD
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.
■ HSTL inputs and Variable drive HSTL output buffers
■ Available in 165-Ball FBGA package (15 x 17 x 1.4 mm)
■ Offered in both Pb-free and non Pb-free packages
■ JTAG 1149.1 compatible test access port
■ Delay Lock Loop (DLL) for accurate data placement
Configurations
With Read Cycle Latency of 2.0 cycles:
CY7C1546V18 – 8M x 8
CY7C1557V18 – 8M x 9
CY7C1548V18 – 4M x 18
CY7C1550V18 – 2M x 36
Selection Guide
375 MHz
375
333 MHz
333
300 MHz
300
Unit
MHz
mA
Maximum Operating Frequency
Maximum Operating Current
x8
x9
1300
1300
1300
1300
1200
1200
1200
1200
1100
1100
x18
x36
1100
1100
Note
1. The QDR consortium specification for V
is 1.5V + 0.1V. The Cypress QDR devices exceed the QDR consortium specification and are capable of supporting V
DDQ
DDQ
= 1.4V to V
.
DD
Cypress Semiconductor Corporation
Document Number: 001-06550 Rev. *D
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised August 7, 2007