Cypress CY7C1464AV33, CY7C1462AV33 Functional Overview, Single Read Accesses, Burst Read Accesses

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CY7C1460AV33

CY7C1462AV33

CY7C1464AV33

Functional Overview

The CY7C1460AV33/CY7C1462AV33/CY7C1464AV33 are synchronous-pipelined Burst NoBL SRAMs designed specifi- cally to eliminate wait states during Write/Read transitions. All synchronous inputs pass through input registers controlled by the rising edge of the clock. The clock signal is qualified with the Clock Enable input signal (CEN). If CEN is HIGH, the clock signal is not recognized and all internal states are maintained. All synchronous operations are qualified with CEN. All data outputs pass through output registers controlled by the rising edge of the clock. Maximum access delay from the clock rise (tCO) is 2.6 ns (250-MHz device).

Accesses can be initiated by asserting all three Chip Enables (CE1, CE2, CE3) active at the rising edge of the clock. If Clock Enable (CEN) is active LOW and ADV/LD is asserted LOW, the address presented to the device will be latched. The access can either be a read or write operation, depending on the status of the Write Enable (WE). BW[x] can be used to conduct byte write operations.

Write operations are qualified by the Write Enable (WE). All writes are simplified with on-chip synchronous self-timed write circuitry.

Three synchronous Chip Enables (CE1, CE2, CE3) and an asynchronous Output Enable (OE) simplify depth expansion. All operations (Reads, Writes, and Deselects) are pipelined. ADV/LD should be driven LOW once the device has been deselected in order to load a new address for the next operation.

Single Read Accesses

A read access is initiated when the following conditions are satisfied at clock rise: (1) CEN is asserted LOW, (2) CE1, CE2, and CE3 are ALL asserted active, (3) the Write Enable input signal WE is deasserted HIGH, and (4) ADV/LD is asserted LOW. The address presented to the address inputs is latched into the Address Register and presented to the memory core and control logic. The control logic determines that a read access is in progress and allows the requested data to propagate to the input of the output register. At the rising edge of the next clock the requested data is allowed to propagate through the output register and onto the data bus within 2.6 ns (250-MHz device) provided OE is active LOW. After the first clock of the read access the output buffers are controlled by OE and the internal control logic. OE must be driven LOW in order for the device to drive out the requested data. During the second clock, a subsequent operation (Read/Write/Deselect) can be initiated. Deselecting the device is also pipelined. Therefore, when the SRAM is deselected at clock rise by one of the chip enable signals, its output will tri-state following the next clock rise.

Burst Read Accesses

The CY7C1460AV33/CY7C1462AV33/CY7C1464AV33 have an on-chip burst counter that allows the user the ability to supply a single address and conduct up to four Reads without reasserting the address inputs. ADV/LD must be driven LOW in order to load a new address into the SRAM, as described in the Single Read Access section above. The sequence of the burst counter is determined by the MODE input signal. A LOW input on MODE selects a linear burst mode, a HIGH selects an interleaved burst sequence. Both burst counters use A0 and A1 in the burst sequence, and will wrap-around when incre- mented sufficiently. A HIGH input on ADV/LD will increment

Document #: 38-05353 Rev. *D

the internal burst counter regardless of the state of chip enables inputs or WE. WE is latched at the beginning of a burst cycle. Therefore, the type of access (Read or Write) is maintained throughout the burst sequence.

Single Write Accesses

Write access are initiated when the following conditions are satisfied at clock rise: (1) CEN is asserted LOW, (2) CE1, CE2, and CE3 are ALL asserted active, and (3) the write signal WE is asserted LOW. The address presented to the address inputs is loaded into the Address Register. The write signals are latched into the Control Logic block.

On the subsequent clock rise the data lines are automatically tri-stated regardless of the state of the OE input signal. This allows the external logic to present the data on DQ and DQP

(DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for CY7C1464AV33, DQa,b,c,d/DQPa,b,c,d for CY7C1460AV33 and DQa,b/DQPa,b for CY7C1462AV33). In addition, the address for the subse- quent access (Read/Write/Deselect) is latched into the Address Register (provided the appropriate control signals are asserted).

On the next clock rise the data presented to DQ and DQP

(DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for CY7C1464AV33, DQa,b,c,d/DQPa,b,c,d for CY7C1460AV33 & DQa,b/DQPa,b for CY7C1462AV33) (or a subset for byte write operations, see Write Cycle Description table for details) inputs is latched into the device and the write is complete.

The data written during the Write operation is controlled by BW (BWa,b,c,d,e,f,g,h for CY7C1464AV33, BWa,b,c,d for CY7C1460AV33 and BWa,b for CY7C1462AV33) signals. The CY7C1460AV33/CY7C1462AV33/CY7C1464AV33 provides byte write capability that is described in the Write Cycle Description table. Asserting the Write Enable input (WE) with the selected Byte Write Select (BW) input will selectively write to only the desired bytes. Bytes not selected during a byte write operation will remain unaltered. A synchronous self-timed write mechanism has been provided to simplify the write operations. Byte write capability has been included in order to greatly simplify Read/Modify/Write sequences, which can be reduced to simple byte write operations.

Becausethe

CY7C1460AV33/CY7C1462AV33/CY7C1464AV33 are common I/O devices, data should not be driven into the device while the outputs are active. The Output Enable (OE) can be deasserted HIGH before presenting data to the DQ and DQP

(DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for CY7C1464AV33, DQa,b,c,d/DQPa,b,c,d for CY7C1460AV33 and DQa,b/DQPa,b for CY7C1462AV33) inputs. Doing so will tri-state the output drivers. As a safety precaution, DQ and DQP

(DQa,b,c,d,e,f,g,h/DQPa,b,c,d,e,f,g,h for CY7C1464AV33, DQa,b,c,d/DQPa,b,c,d for CY7C1460AV33 and DQa,b/DQPa,b for CY7C1462AV33) are automatically tri-stated during the data portion of a write cycle, regardless of the state of OE.

Burst Write Accesses

The CY7C1460AV33/CY7C1462AV33/CY7C1464AV33 has an on-chip burst counter that allows the user the ability to supply a single address and conduct up to four WRITE opera- tions without reasserting the address inputs. ADV/LD must be driven LOW in order to load the initial address, as described in the Single Write Access section above. When ADV/LD is driven HIGH on the subsequent clock rise, the chip enables (CE1, CE2, and CE3) and WE inputs are ignored and the burst

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Contents Cypress Semiconductor Corporation FeaturesLogic Block Diagram-CY7C1460AV33 1M x Functional Description250 MHz 200 MHz 167 MHz Unit Logic Block Diagram-CY7C1462AV33 2M xLogic Block Diagram-CY7C1464AV33 512K x Selection Guide2M × Pin Configurations Pin Tqfp PinoutCY7C1462AV33 2M × Pin Name Type Pin Description Pin DefinitionsPower supply for the I/O circuitry Power supply inputs to the core of the deviceClock input to the Jtag circuitry Burst Write Accesses Single Read AccessesBurst Read Accesses Single Write AccessesLinear Burst Address Table Mode = GND Interleaved Burst Address Table Mode = Floating or VDDZZ Mode Electrical Characteristics Function CY7C1462AV33 2,8 Partial Write Cycle Description 1, 2, 3Stall Function CY7C1460AV33Performing a TAP Reset TAP Controller Block Diagram TAP Controller State DiagramDisabling the Jtag Feature Test Access Port TAPTAP Instruction Set Bypass RegisterSet-up Times TAP TimingParameter Description Min Max Unit Clock Output TimesIdentification Register Definitions TAP DC Electrical Characteristics And Operating Conditions3V TAP AC Test Conditions 5V TAP AC Test ConditionsInstruction Code Description Scan Register SizesIdentification Codes Register Name Bit Size ×36 Bit Size ×18 Bit Size ×72CY7C1460AV33 1M x 36, CY7C1462AV33 2M x Bit# Ball ID Ball Fbga Boundary Scan OrderBit# Ball ID CY7C14604V33 512K x Bit# Ball ID Ball BGA Boundary Scan Order 13Ambient Range Electrical Characteristics Over the Operating Range15Maximum Ratings Operating RangeThermal Resistance17 Capacitance17AC Test Loads and Waveforms 250 200 167 Parameter Description Unit Min Max Switching Characteristics Over the Operating Range 22Read/Write/Timing24, 25 Switching WaveformsNOP,STALL and Deselect Cycles24, 25 ZZ Mode Timing28Ordering Information 250 Pin Tqfp 14 x 20 x 1.4 mm Package DiagramsBall Fbga 15 x 17 x 1.4 mm Ball Fbga 14 x 22 x 1.76 mm Document History ECN No Issue Date Orig. Description of Change

CY7C1462AV33, CY7C1464AV33, CY7C1460AV33 specifications

The Cypress CY7C1460AV33, CY7C1464AV33, and CY7C1462AV33 are high-performance, low-power asynchronous SRAM devices that find wide applications in various electronic systems, encompassing telecommunications, computing, and consumer electronics. These SRAM products are particularly popular for their speed, efficiency, and versatility in a range of data processing applications.

A key feature of the CY7C1460AV33 is its 64K x 16 memory architecture, while the CY7C1464AV33 offers a 256K x 16 configuration, and the CY7C1462AV33 provides a 128K x 16 setup. This allows designers to tailor their memory requirements based on the specific demands of their applications, promoting system optimization and enhancing performance.

One of the standout characteristics of these SRAM devices is their high-speed operation. With access times as low as 10 nanoseconds, they are capable of supporting demanding applications that necessitate rapid data retrieval and storage. This performance is complemented by a low cycle time, which contributes to faster data rates, enabling seamless data flow and efficient processing capabilities.

Low power consumption is another defining feature of the CY7C1460AV33, CY7C1464AV33, and CY7C1462AV33. These devices utilize advanced CMOS technology, ensuring minimal energy usage without sacrificing performance. This is particularly advantageous for battery-operated devices and applications where energy efficiency is critical.

The SRAM devices also boast robust reliability and environmental tolerance. They are designed to operate over a wide temperature range, making them suitable for various operating conditions. Additionally, the use of advanced process technology ensures data integrity and durability, allowing them to survive in harsh environments.

Furthermore, the devices support a simple interfacing design, enabling easy integration into existing systems. They feature dual-chip select and byte write functionality, which enhances flexibility in memory handling, providing the capability to manage data more effectively.

In summary, the Cypress CY7C1460AV33, CY7C1464AV33, and CY7C1462AV33 offer high-speed, low-power, and highly reliable SRAM solutions suitable for various applications. With their advanced technology and robust characteristics, these devices are invaluable in modern electronic design, enabling innovation and performance optimization across diverse fields.
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