Cypress manual CY7C1541V18, CY7C1556V18 CY7C1543V18, CY7C1545V18, Features, Configurations

CY7C1541V18, CY7C1556V18

CY7C1543V18, CY7C1545V18

72-Mbit QDR™-II+ SRAM 4-Word Burst Architecture (2.0 Cycle Read Latency)

Features

■Separate independent read and write data ports

❐Supports concurrent transactions

■375 MHz clock for high bandwidth

■4-word burst for reducing address bus frequency

■Double Data Rate (DDR) interfaces on both read and write ports (data transferred at 750 MHz) at 375 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 both read and write ports

■Separate port selects for depth expansion

■Synchronous internally self-timed writes

■Available in x8, x9, x18, and x36 configurations

■Full data coherency, providing most current data

■Core VDD = 1.8V ± 0.1V; IO VDDQ = 1.4V to VDD [1]

■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:

CY7C1541V18 – 8M x 8

CY7C1556V18 – 8M x 9

CY7C1543V18 – 4M x 18

CY7C1545V18 – 2M x 36

Functional Description

The CY7C1541V18, CY7C1556V18, CY7C1543V18, and CY7C1545V18 are 1.8V Synchronous Pipelined SRAMs, equipped with QDR-II+ architecture. Similar to QDR-II archi- tecture, QDR-II+ SRAMs 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 “turn-around” the data bus that exists with common IO 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 8-bit words (CY7C1541V18), 9-bit words (CY7C1556V18), 18-bit words (CY7C1543V18), or 36-bit words (CY7C1545V18) that burst sequentially into or out of the device. Because data is trans- ferred into and out of the device on every rising edge of both input clocks (K and K), memory bandwidth is maximized while simpli- fying system design by eliminating bus “turn-arounds”.

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.

Selection Guide

Description		375 MHz	333 MHz	300 MHz	Unit
Maximum Operating Frequency		375	333	300	MHz
Maximum Operating Current	x8	1300	1200	1100	mA
	x9	1300	1200	1100
	x18	1300	1200	1100
	x36	1370	1230	1140

Note

1.The QDR consortium specification for VDDQ is 1.5V + 0.1V. The Cypress QDR devices exceed the QDR consortium specification and are capable of supporting VDDQ = 1.4V to VDD.

Cypress Semiconductor Corporation • 198 Champion Court	•	San Jose, CA 95134-1709	•	408-943-2600
Document Number: 001-05389 Rev. *F		Revised March 06, 2008

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