CY7C1317CV18, CY7C1917CV18 CY7C1319CV18, CY7C1321CV18

after the read(s), the stored data from the earlier write is written into the SRAM array. This is called a posted write.

If a read is performed on the same address on which a write is performed in the previous cycle, the SRAM reads out the most current data. The SRAM does this by bypassing the memory array and reading the data from the registers.

Depth Expansion

Depth expansion requires replicating the LD control signal for each bank. All other control signals can be common between banks as appropriate.

Programmable Impedance

An external resistor, RQ, must be connected between the ZQ pin on the SRAM and VSS to enable the SRAM to adjust its output 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 24.

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 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.

Document Number: 001-07161 Rev. *D

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Cypress CY7C1319CV18, CY7C1321CV18, CY7C1317CV18, CY7C1917CV18 manual Depth Expansion, Programmable Impedance, Echo Clocks
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CY7C1321CV18, CY7C1917CV18, CY7C1319CV18, CY7C1317CV18 specifications

Cypress Semiconductor Corporation, a leading provider of advanced embedded memory solutions, offers a series of high-performance SRAM (Static Random Access Memory) devices ideal for a variety of applications. Among these devices are the CY7C1317CV18, CY7C1319CV18, CY7C1917CV18, and CY7C1321CV18. These components are designed to meet the growing demands for non-volatile memory in consumer electronics, automotive systems, telecommunications, and industrial applications.

The CY7C1317CV18 and CY7C1319CV18 are both 256K-bit static RAMs with distinct features. The CY7C1317CV18 offers a dual-port architecture, enabling concurrent access from multiple sources, which substantially enhances performance in data-intensive applications. On the other hand, the CY7C1319CV18 is designed for single-port access, making it ideal for simpler applications that do not require simultaneous data reads and writes.

Further extending Cypress's SRAM portfolio, the CY7C1917CV18 provides a 2M-bit memory configuration with fast access times, high-density storage, and low power consumption. It is particularly well-suited for applications needing quick data retrieval while maintaining efficiency. The architecture of the CY7C1917CV18 allows it to be integrated seamlessly into systems requiring reliable and robust data storage.

Completing the lineup is the CY7C1321CV18, which features an innovative 1M-bit SRAM design. This SRAM is known for its low latency and high speed, making it an excellent choice for high-performance computing applications. It supports a wide operating voltage range and provides a reliable solution for volatile memory needs, especially in fast caching scenarios.

These SRAM devices utilize advanced CMOS technology to achieve high speed and low power characteristics, making them competitive choices in the market. Their robust performance ensures that they satisfy the stringent requirements of various applications, including high-speed networking, graphics processing, and instrumentation.

In terms of reliability, all four devices are built to endure challenging operating conditions and provide excellent data retention. They are offered in compact packages that facilitate easy integration into PCBs, optimizing space and enhancing design flexibility. The combination of performance, low power consumption, and scalability makes Cypress's SRAM products particularly advantageous for next-generation applications across multiple industries.
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