Application Example, Echo Clocks, SRAM#1 ZQ

CY7C1316CV18, CY7C1916CV18 CY7C1318CV18, CY7C1320CV18

driver impedance. The value of RQ must be 5x the value of the intended line impedance driven by the SRAM. The allowable range of RQ to guarantee impedance matching with a tolerance of ±15% is between 175Ω and 350Ω, with VDDQ = 1.5V. The output impedance is adjusted every 1024 cycles at power up to account for drifts in supply voltage and temperature.

Echo Clocks

Echo clocks are provided on the DDR-II to simplify data capture on high-speed systems. Two echo clocks are generated by the DDR-II. CQ is referenced with respect to C and CQ is referenced with respect to C. These are free running clocks and are synchro- nized to the output clock of the DDR-II. In the single clock mode, CQ is generated with respect to K and CQ is generated with respect to K. The timing for the echo clocks is shown in Switching Characteristics on page 23.

DLL

These chips use a Delay Lock Loop (DLL) that is designed to function between 120 MHz and the specified maximum clock frequency. During power up, when the DOFF is tied HIGH, the DLL is locked after 1024 cycles of stable clock. The DLL can also be reset by slowing or stopping the input clocks K and K for a minimum of 30 ns. However, it is not necessary to reset the DLL to lock it to the desired frequency. The DLL automatically locks 1024 clock cycles after a stable clock is presented. The DLL may be disabled by applying ground to the DOFF pin. When the DLL is turned off, the device behaves in DDR-I mode (with one cycle latency and a longer access time). For information refer to the application note DLL Considerations in QDRII™/DDRII.

Application Example

Figure 1 shows two DDR-II used in an application.

Figure 1. Application Example

SRAM#1 ZQ

DQCQ/CQ#

A LD# R/W# C C# K K#

	DQ
BUS	Addresses
MASTER	Cycle Start#
(CPU	R/W#
or	Return CLK	Vterm = 0.75V
ASIC)	Source CLK	Vterm = 0.75V
ASIC)	Source CLK	R = 50ohms
	Return CLK#	R = 50ohms
	Return CLK#	Vterm = 0.75V
	Source CLK#	Vterm = 0.75V
	Source CLK#
Echo Clock1/Echo Clock#1
Echo Clock2/Echo Clock#2

R = 250ohms	SRAM#2		ZQ
	SRAM#2		ZQ
	DQ	CQ/CQ#
	DQ	CQ/CQ#
	A LD# R/W# C C#	K K#

R = 250ohms

Document Number: 001-07160 Rev. *E

Page 9 of 29

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CY7C1320CV18, CY7C1916CV18, CY7C1316CV18, CY7C1318CV18 specifications

Cypress Semiconductor, a leading provider of high-performance memory solutions, offers a range of Static Random-Access Memory (SRAM) products ideal for various applications. Among these are the CY7C1320CV18, CY7C1916CV18, CY7C1316CV18, and CY7C1318CV18, each designed to meet the demands of modern electronic systems with distinctive features, technologies, and characteristics.

The CY7C1320CV18 is a high-performance 2-Mbit SRAM that operates at a voltage of 1.8V. Designed with speed in mind, it has access times as low as 12 ns, making it suitable for applications requiring quick data retrieval. The device features a simple asynchronous interface, allowing it to be easily integrated into various circuits. With a low power consumption profile and the ability to operate under a wide temperature range, the CY7C1320CV18 is an ideal choice for battery-operated devices and industrial environments.

Following closely, the CY7C1916CV18 is a highly integrated, 16-Mbit synchronous SRAM. This device stands out due to its robust data transfer capabilities, supporting a single-cycle read and write operation, which greatly enhances system performance. The device operates with a supply voltage of 1.8V and features an impressive latency, making it perfect for high-speed applications such as digital signal processing and telecommunications. The unique pipelined architecture allows for higher throughput and efficiency in memory access.

The CY7C1316CV18 is another notable member of this family, featuring 16K x 8 bits of memory. It is characterized by low power consumption and a fast access time, which helps to reduce latency in critical applications. With a simple asynchronous interface and competitive pricing, the CY7C1316CV18 is suitable for consumer electronics and automotive applications that require reliable performance.

Lastly, the CY7C1318CV18 is a comprehensive solution featuring 32K x 8 bits of memory. This device also operates with low power and high speed, making it efficient for caching, buffering, and temporary storage applications. Its compatibility with industry standards makes it easily integrable into existing systems.

In summary, the CY7C1320CV18, CY7C1916CV18, CY7C1316CV18, and CY7C1318CV18 SRAM devices from Cypress Semiconductor showcase cutting-edge technology, high performance, and versatility, catering to the evolving needs of today's electronics, from telecommunications to consumer devices. Their low power consumption, high-speed access, and reliable data integrity make them essential components in modern electronic designs.

Cypress CY7C1320CV18, CY7C1318CV18 manual Application Example, Echo Clocks, SRAM#1 ZQ, SRAM#2

Models: CY7C1320CV18 CY7C1916CV18 CY7C1316CV18 CY7C1318CV18