Cypress CY7C1523AV18, CY7C1529AV18, CY7C1524AV18 Power Up Sequence in DDR-II Sram, DLL Constraints

Page 19

CY7C1522AV18, CY7C1529AV18 CY7C1523AV18, CY7C1524AV18

Power Up Sequence in DDR-II SRAM

DDR-II SRAMs must be powered up and initialized in a predefined manner to prevent undefined operations.

Power Up Sequence

■Apply power and drive DOFF either HIGH or LOW (All other inputs can be HIGH or LOW).

❐Apply VDD before VDDQ.

❐Apply VDDQ before VREF or at the same time as VREF.

❐Drive DOFF HIGH.

DLL Constraints

■DLL uses K clock as its synchronizing input. The input must have low phase jitter, which is specified as tKC Var.

■The DLL functions at frequencies down to 120 MHz.

■If the input clock is unstable and the DLL is enabled, then the DLL may lock onto an incorrect frequency, causing unstable SRAM behavior. To avoid this, provide1024 cycles stable clock to relock to the desired clock frequency.

■Provide stable DOFF (HIGH), power and clock (K, K) for 1024 cycles to lock the DLL.

K

K

VDD/ VDDQ

DOFF

Figure 3. Power Up Waveforms

~ ~

 

~ ~

 

Unstable Clock

> 1024 Stable clock

Start Normal

 

 

Operation

Clock Start (Clock Starts after VDD/ V DDQ Stable)

VDD/ V DDQ Stable (< +/- 0.1V DC per 50ns )

Fix High (or tie to VDDQ)

Document #: 001-06981 Rev. *D

Page 19 of 30

[+] Feedback

Page 18 Page 20
Image 19
Page 18 Page 20
Contents Selection Guide FeaturesConfigurations Functional DescriptionDoff Logic Block Diagram CY7C1522AV18CLK Logic Block Diagram CY7C1524AV18 Logic Block Diagram CY7C1523AV18CY7C1529AV18 8M x Pin ConfigurationBall Fbga 15 x 17 x 1.4 mm Pinout CY7C1522AV18 8M xCY7C1524AV18 2M x CY7C1523AV18 4M xPin Name Pin Description Pin DefinitionsSynchronous Read/Write Input. When TDO for Jtag Power Supply Inputs to the Core of the DevicePower Supply Inputs for the Outputs of the Device Referenced with Respect toFunctional Overview Application Example Application ExampleBWS0/ BWS1 NWS0 NWS1 Truth TableWrite Cycle Descriptions LD R/WBWS0 BWS1 BWS2 BWS3 BWS0Ieee 1149.1 Serial Boundary Scan Jtag Idcode TAP Controller State Diagram TCK TAP Controller Block DiagramTAP Electrical Characteristics TDITAP Timing and Test Conditions TAP AC Switching CharacteristicsRegister Name Bit Size Identification Register DefinitionsScan Register Sizes Instruction CodesBit # Bump ID Boundary Scan OrderPower Up Sequence Power Up Sequence in DDR-II SramDLL Constraints DC Electrical Characteristics Electrical CharacteristicsMaximum Ratings AC Electrical Characteristics Parameter Description Test Conditions Fbga Unit CapacitanceThermal Resistance Parameter Description Test Conditions Max UnitHigh Switching CharacteristicsLOW DLL Timing Static to DLL ResetNOP Read Write Switching WaveformsBurst Ordering Information 250 167 Ball Fbga 15 x 17 x 1.4 mm Package DiagramREV ECN no Submission ORIG. Description of Change Date Sales, Solutions, and Legal InformationWorldwide Sales and Design Support Products PSoC Solutions Document History

CY7C1529AV18, CY7C1523AV18, CY7C1524AV18, CY7C1522AV18 specifications

Cypress Semiconductor has established itself as a prominent player in the memory solutions market, and its family of high-performance synchronous static random-access memory (SRAM) devices has garnered significant attention. Among these, the CY7C1522AV18, CY7C1524AV18, CY7C1523AV18, and CY7C1529AV18 stand out due to their advanced features and reliable performance.

The CY7C1522AV18 is a 2 Megabit SRAM device designed to deliver fast access times with a dual-port architecture. This memory solution supports a 3.0V to 3.6V power supply range. With a high-speed operation of up to 167 MHz, it is ideal for applications that require rapid data processing and retrieval. Its unique architecture allows simultaneous read and write operations, which enhances throughput and efficiency in data handling.

Conversely, the CY7C1524AV18 is a 4 Megabit SRAM that builds upon these capabilities, offering an even larger storage option while maintaining similar speed and voltage specifications. Both devices come with Cyclical Redundancy Check (CRC) for data integrity, ensuring reliability in mission-critical applications. Additionally, these SRAMs feature a simple asynchronous interface, making integration into existing systems remarkably straightforward.

The CY7C1523AV18 offers a balance of features with its 3 Megabit capacity. Similar to its counterparts, this device also presents dual-port capabilities, which facilitate quick data access without bottlenecks, proving advantageous in high-performance computing environments.

Lastly, the CY7C1529AV18 rounds out the family with its impressive 9 Megabit capacity, providing ample memory for more extensive applications. Its enhanced architecture makes it suitable for advanced embedded systems where speed and reliability are paramount.

All four devices leverage Cypress’s innovative Synchronous SRAM technology, which offers low latency and high bandwidth, making them suited for high-performance applications such as networking, telecommunications, and industrial control systems. The memory chips are built with robust features including low power consumption modes and wide operating temperature ranges, enhancing their versatility in various environments.

In conclusion, the CYPRESS CY7C1522AV18, CY7C1524AV18, CY7C1523AV18, and CY7C1529AV18 are exemplary SRAM solutions that combine speed, capacity, and reliability, catering to a broad spectrum of contemporary electronic systems. Whether for embedded applications or high-speed network devices, these memory solutions continue to be at the forefront of technology advancements.
Top Page Image Contents