Cypress Semiconductor Corp CY7C1243KV18-450BZC

Overview

CY7C1243KV18 from Cypress Semiconductor is a 2M × 18, 36-Mbit QDR® II+ SRAM with separate read/write ports, 450 MHz clock operation (900 Mbps DDR data rate), 2.0-cycle read latency, and 1.8 V core / 1.4–1.8 V I/O supply. It delivers concurrent high-bandwidth memory access for network packet buffering in telecom line cards.

For engineers reviewing the CY7C1243KV18 datasheet, CY7C1243KV18 pinout, CY7C1243KV18 application, or CY7C1243KV18 equivalent, key selection criteria include burst depth (four 18-bit words), echo clock timing (CQ/CQ), QVLD validity signaling, DOFF-configurable latency mode, and HSTL-18 I/O compliance.

Technical Context

The device implements a true dual-port synchronous architecture with independent K and K clocks driving separate input registers for address/data/control, enabling full concurrency between read and write operations without bus turnaround. Its internal PLL aligns output data placement to echo clocks CQ/CQ for reliable capture at 900 Mbps.

All transactions are four-word bursts initiated on rising edges of K (read) or K (write); address latching alternates per port, and depth expansion uses RPS/WPS with byte-write selects BWS0–BWS1. Core logic operates at 1.8 V ±0.1 V, while I/O buffers support programmable impedance via ZQ pin tied to external resistor.

Key Specifications

Pinout & Package

Package: 165-ball FBGA (13 mm × 15 mm × 1.4 mm), RoHS-compliant, 0.8 mm ball pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-bandwidth dual-port SRAM applications.

Compared with IDT72T3615L10BG and IS61WV102418B, CY7C1243KV18 provides 35% higher bandwidth, deterministic 2-cycle latency with QVLD, and built-in echo clocks-enabling simpler FPGA interface design and higher system throughput in telecom and test equipment.

Availability

CY7C1243KV18 is available at Aetrix Electronics and suitable for network packet buffering, high-speed test equipment memory, telecom line card control memory, and real-time video frame buffering requiring stable component supply and long-term production continuity.

Supply support for CY7C1243KV18 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Cypress Semiconductor (now part of Infineon Technologies) designs high-performance memory and programmable solutions for networking, automotive, and industrial applications.

CY7C1243KV18 belongs to the QDR® II+ SRAM product line, engineered specifically for deterministic, low-latency, concurrent memory access in packet-switched infrastructure and high-speed instrumentation.

FAQ

What is the function of the DOFF pin on CY7C1243KV18?

The DOFF pin disables the internal PLL when pulled LOW, reverting the device to QDR I mode with 1-cycle read latency and a maximum clock frequency of 167 MHz. When pulled HIGH (or via 10 kΩ pull-up), the PLL is active, enabling 2.0-cycle latency and full 450 MHz operation. This pin allows runtime mode switching between performance and compatibility modes.

How does the ZQ pin affect signal integrity?

The ZQ pin connects to an external resistor to ground to calibrate the output driver impedance of Q[17:0], CQ, and CQ pins to 0.2 × RQ. This on-die termination matches PCB trace impedance, reducing reflections and improving eye diagram margins at 900 Mbps DDR rates-eliminating the need for discrete series or parallel termination resistors.

Can CY7C1243KV18 perform partial writes without reading existing data?

Yes. Using BWS0 (controls D[8:0]) and BWS1 (controls D[17:9]), the device supports byte-selective writes. When a BWS signal is deasserted, the corresponding 9-bit data segment is ignored during the write cycle, leaving those bits unchanged. This enables efficient updates to sub-word fields without requiring read-modify-write sequences.

What is the role of QVLD in system timing design?

QVLD is a source-synchronous validity flag edge-aligned with CQ and CQ, indicating when Q[17:0] data is stable and valid. It replaces fixed-latency assumptions in FPGA capture logic, allowing dynamic alignment to actual data arrival-critical for robust timing closure in systems operating near the 450 MHz limit with varying PVT conditions.