Cypress CY7C1474V25 manual Features, Functional Description, Logic Block Diagram-CY7C1470V25 2M x

CY7C1470V25

CY7C1472V25

CY7C1474V25

72-Mbit(2M x 36/4M x 18/1M x 72) Pipelined SRAM with NoBL™ Architecture

Features

•Pin-compatible and functionally equivalent to ZBT™

•Supports 250-MHz bus operations with zero wait states

—Available speed grades are 250, 200 and 167 MHz

•Internally self-timed output buffer control to eliminate the need to use asynchronous OE

•Fully registered (inputs and outputs) for pipelined operation

•Byte Write capability

•Single 2.5V power supply

•2.5V/1.8V I/O supply (VDDQ)

•Fast clock-to-output times

—3.0 ns (for 250-MHz device)

•Clock Enable (CEN) pin to suspend operation

•Synchronous self-timed writes

•CY7C1470V25, CY7C1472V25 available in JEDEC-standard lead-free 100-pin TQFP, lead-free and non-lead-free 165-ball FBGA package. CY7C1474V25 available in lead-free and non-lead-free 209 ball FBGA package

•IEEE 1149.1 JTAG Boundary Scan compatible

•Burst capability—linear or interleaved burst order

•“ZZ” Sleep Mode option and Stop Clock option

Functional Description

The CY7C1470V25/CY7C1472V25/CY7C1474V25 are 2.5V, 2M x 36/4M x 18/1M x 72 Synchronous pipelined burst SRAMs with No Bus Latency™ (NoBL™) logic, respectively. They are designed to support unlimited true back-to-back Read/Write

operations with no wait states. The CY7C1470V25/CY7C1472V25/CY7C1474V25 are equipped with the advanced (NoBL) logic required to enable consec- utive Read/Write operations with data being transferred on every clock cycle. This feature dramatically improves the throughput of data in systems that require frequent Write/Read transitions. The CY7C1470V25/CY7C1472V25/CY7C1474V25 are pin-compatible and functionally equivalent to ZBT devices.

All synchronous inputs pass through input registers controlled by the rising edge of the clock. All data outputs pass through output registers controlled by the rising edge of the clock. The clock input is qualified by the Clock Enable (CEN) signal, which when deasserted suspends operation and extends the previous clock cycle. Write operations are controlled by the Byte Write Selects (BWa–BWhfor CY7C1474V25, BWa–BWdfor CY7C1470V25 and BWa–BWbfor CY7C1472V25) and a Write Enable (WE) input. All writes are conducted with on-chip synchronous self-timed write circuitry.

Three synchronous Chip Enables (CE1, CE2, CE3) and an asynchronous Output Enable (OE) provide for easy bank selection and output tri-state control. In order to avoid bus contention, the output drivers are synchronously tri-stated during the data portion of a write sequence.

Logic Block Diagram-CY7C1470V25 (2M x 36)
	A0, A1, A	ADDRESS
		REGISTER 0	A1	D1	Q1	A1'
	MODE		A0	D0 BURST Q0 A0'
			ADV/LD	LOGIC
CLK	C
			C
CEN
		WRITE ADDRESS	WRITE ADDRESS
		REGISTER 1	REGISTER 2
								S	O		O
									U	D
								E	T		U
									P	A	T
								N
									U	T	P
	ADV/LD							S	T	A	U
									R		T
			WRITE REGISTRY				MEMORY	E		S	B
	BWa		AND DATA COHERENCY			WRITE			E
							ARRAY
	BWb		CONTROL LOGIC			DRIVERS		A	G	T	U
									I		F
	BWc							M	S	E
											F
	BWd							P	T	E	E
									E
	WE							S	R	R	R
									S	I	S
									E	N	E
										G
							INPUT	E		INPUT	E
							REGISTER 1			REGISTER 0
	OE	READ LOGIC
	CE1
	CE2
	CE3
	ZZ	SLEEP
		CONTROL

DQs DQPa DQPb DQPc DQPd

Cypress Semiconductor Corporation	•	198 Champion Court • San Jose, CA 95134-1709	•	408-943-2600
Document #: 38-05290 Rev. *I		Revised June 21, 2006

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