Cypress CY7C1318BV18, CY7C1320BV18, CY7C1316BV18, CY7C1916BV18 manual Functional Overview

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CY7C1316BV18, CY7C1916BV18 CY7C1318BV18, CY7C1320BV18

Functional Overview

The CY7C1316BV18, CY7C1916BV18, CY7C1318BV18, and CY7C1320BV18 are synchronous pipelined Burst SRAMs equipped with a DDR interface.

Accesses are initiated on the rising edge of the positive input clock (K). All synchronous input timing is referenced from the rising edge of the input clocks (K and K) and all output timing is referenced to the rising edge of the output clocks (C/C, or K/K when in single clock mode).

All synchronous data inputs (D[x:0]) pass through input registers controlled by the rising edge of the input clocks (K and K). All synchronous data outputs (Q[x:0]) pass through output registers controlled by the rising edge of the output clocks (C/C, or K/K when in single-clock mode).

All synchronous control (R/W, LD, BWS[0:X]) inputs pass through input registers controlled by the rising edge of the input clock (K).

CY7C1318BV18 is described in the following sections. The same basic descriptions apply to CY7C1316BV18, CY7C1916BV18, and CY7C1320BV18.

mation presented to D[17:0] is also stored into the write data register, provided BWS[1:0] are both asserted active. The 36 bits of data are then written into the memory array at the specified location. Write accesses can be initiated on every rising edge of the positive input clock (K). This pipelines the data flow such that 18 bits of data can be transferred into the device on every rising edge of the input clocks (K and K).

When Write access is deselected, the device ignores all inputs after the pending write operations are completed.

Byte Write Operations

Byte write operations are supported by the CY7C1318BV18. A write operation is initiated as described in the Write Operations section. The bytes that are written are determined by BWS0 and BWS1, which are sampled with each set of 18-bit data words. Asserting the appropriate Byte Write Select input during the data portion of a write latches the data being presented and writes it into the device. Deasserting the Byte Write Select input during the data portion of a write enables the data stored in the device for that byte to remain unaltered. This feature can be used to simplify read/modify/write operations to a byte write operation.

Read Operations

The CY7C1318BV18 is organized internally as a single array of 1M x 18. Accesses are completed in a burst of two sequential 18-bit data words. Read operations are initiated by asserting R/W HIGH and LD LOW at the rising edge of the positive input clock (K). The address presented to address inputs is stored in the read address register and the least significant bit of the address is presented to the burst counter. The burst counter increments the address in a linear fashion. Following the next K clock rise, the corresponding 18-bit word of data from this address location is driven onto Q[17:0], using C as the output timing reference. On the subsequent rising edge of C the next 18-bit data word from the address location generated by the burst counter is driven onto Q[17:0]. The requested data is valid 0.45 ns from the rising edge of the output clock (C or C, or K and K when in single clock mode, 200 MHz and 250 MHz device). To maintain the internal logic, each read access must be allowed to complete. Read accesses can be initiated on every rising edge of the positive input clock (K).

The CY7C1318BV18 first completes the pending read transac- tions, when read access is deselected. Synchronous internal circuitry automatically tri-states the output following the next rising edge of the positive output clock (C). This enables a seamless transition between devices without the insertion of wait states in a depth expanded memory.

Write Operations

Write operations are initiated by asserting R/W LOW and LD LOW at the rising edge of the positive input clock (K). The address presented to address inputs is stored in the write address register and the least significant bit of the address is presented to the burst counter. The burst counter increments the address in a linear fashion. On the following K clock rise the data presented to D[17:0] is latched and stored into the 18-bit write data register, provided BWS[1:0] are both asserted active. On the subsequent rising edge of the negative input clock (K) the infor-

Single Clock Mode

The CY7C1318BV18 can be used with a single clock that controls both the input and output registers. In this mode the device recognizes only a single pair of input clocks (K and K) that control both the input and output registers. This operation is identical to the operation if the device had zero skew between the K/K and C/C clocks. All timing parameters remain the same in this mode. To use this mode of operation, tie C and C HIGH at power on. This function is a strap option and not alterable during device operation.

DDR Operation

The CY7C1318BV18 enables high-performance operation through high clock frequencies (achieved through pipelining) and double data rate mode of operation. The CY7C1318BV18 requires a single No Operation (NOP) cycle during transition from a read to a write cycle. At higher frequencies, some appli- cations may require a second NOP cycle to avoid contention.

If a read occurs after a write cycle, address and data for the write are stored in registers. The write information must be stored because the SRAM cannot perform the last word write to the array without conflicting with the read. The data stays in this register until the next write cycle occurs. On the first write cycle 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.

Document Number: 38-05621 Rev. *D

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Contents Features ConfigurationsFunctional Description Selection GuideLogic Block Diagram CY7C1316BV18 Logic Block Diagram CY7C1916BV18Doff CLKBWS Logic Block Diagram CY7C1318BV18Logic Block Diagram CY7C1320BV18 Pin Configuration Ball Fbga 13 x 15 x 1.4 mm PinoutCY7C1316BV18 2M x CY7C1916BV18 2M xCY7C1318BV18 1M x CY7C1320BV18 512K xSynchronous Read/Write Input. When Pin DefinitionsPin Name Pin Description Power Supply Inputs to the Core of the Device Power Supply Inputs for the Outputs of the DeviceReferenced with Respect to TDO for JtagFunctional Overview Application Example Programmable ImpedanceEcho Clocks SRAM#1 ZQWrite Cycle Descriptions OperationFirst Address External Second Address Internal CommentsWrite cycle description table for CY7C1916BV18 follows Write cycle description table for CY7C1320BV18 followsDevice Into the device. D359 remains unalteredIeee 1149.1 Serial Boundary Scan Jtag Idcode TAP Controller State Diagram State diagram for the TAP controller followsTAP Controller Block Diagram TAP Electrical CharacteristicsTAP AC Switching Characteristics TAP Timing and Test ConditionsIdentification Register Definitions Scan Register SizesInstruction Codes Register Name Bit SizeBoundary Scan Order Bit # Bump IDDLL Constraints Power Up Sequence in DDR-II SramPower Up Sequence Maximum Ratings Electrical CharacteristicsDC Electrical Characteristics Input LOW Voltage Vref Document Number 38-05621 Rev. *D AC Electrical CharacteristicsInput High Voltage Vref + Capacitance Thermal ResistanceParameter Description Test Conditions Max Unit Parameter Description Test Conditions Fbga UnitParameter Min Max Parameter Min Max Output Times DLL TimingSwitching Waveforms DON’T Care UndefinedOrdering Information 250 167 Package Diagram Ball Fbga 13 x 15 x 1.4 mmSYT NXRSales, Solutions, and Legal Information Worldwide Sales and Design Support Products PSoC SolutionsVKN/PYRS USB

CY7C1316BV18, CY7C1916BV18, CY7C1320BV18, CY7C1318BV18 specifications

The Cypress CY7C1318BV18, CY7C1320BV18, CY7C1916BV18, and CY7C1316BV18 are advanced synchronous static RAM (SRAM) devices designed to meet the high-performance requirements of modern computing systems. Offering a blend of high speed, low power consumption, and large storage capacities, these chips are widely utilized in applications such as networking equipment, telecommunications, and high-speed data processing.

The CY7C1318BV18 is a 2 Megabit SRAM that operates at a 2.5V supply voltage. It features a fast access time of 10ns, making it an excellent choice for systems that require rapid data retrieval. Its asynchronous interface simplifies integration into a wide range of devices. In terms of power efficiency, the CY7C1318BV18 has a low operating current, ensuring that it can be utilized in battery-powered applications without significantly draining power.

Similarly, the CY7C1320BV18 offers a larger 256 Kbit capacity while maintaining the same low-voltage operation and performance characteristics. This chip also features a synchronous interface, supporting high-speed data transfer rates that are ideal for networking and communication devices. The CY7C1320BV18's features include deep-write operation capabilities, enhancing its performance in write-intensive applications.

The CY7C1916BV18 takes performance a step further with its 32 Megabit capacity, suitable for applications requiring extensive memory resources. This device also supports advanced functions such as burst read modes, allowing for faster sequential data access. With its low-latency performance, the CY7C1916BV18 is an excellent choice for applications like digital signal processing and real-time data analysis.

Lastly, the CY7C1316BV18 is another variant offering 1 Megabit of storage. It combines high-speed functionality with low power usage, supporting a wide range of applications including consumer electronics and automotive systems. Its robust design ensures reliability under varying environmental conditions.

All of these SRAM devices incorporate Cypress’s advanced semiconductor technology, providing a combination of speed, efficiency, and reliability. They are available in various package options, which facilitate easy integration into diverse system designs. Overall, the Cypress CY7C1318BV18, CY7C1320BV18, CY7C1916BV18, and CY7C1316BV18 exemplify the company’s commitment to delivering high-quality memory solutions that cater to the evolving needs of the electronic industry.
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