Infineon Technologies CY7C1297H-133AXC

Overview

CY7C1297H-133AXC from Cypress Semiconductor is a 1-Mbit (64K × 18) synchronous flow-through SRAM with 3.3V core and 2.5V/3.3V I/O supplies, designed for high-speed secondary cache interfacing in Pentium-class microprocessor systems. It delivers 6.5 ns clock-to-output access time at 133 MHz, supports user-selectable linear or interleaved burst sequences via MODE pin, and features synchronous self-timed write, asynchronous OE/ZZ control, and JEDEC-standard 100-pin TQFP packaging.

For engineers reviewing the CY7C1297H-133AXC datasheet, CY7C1297H-133AXC pinout, CY7C1297H-133AXC application, or CY7C1297H-133AXC equivalent, key selection criteria include burst sequence compatibility (Intel Pentium vs. linear), VDDQ voltage flexibility (2.5V/3.3V), synchronous address strobe support (ADSP/ADSC), ZZ sleep mode timing (2tCYC entry/exit), and byte-write granularity (BWA/BWB + BWE).

Technical Context

The CY7C1297H-133AXC implements a 2-bit on-chip wraparound burst counter fed by A[1:0], enabling four-word burst reads/writes with deterministic address sequencing. Its synchronous interface registers all control and address inputs on CLK rising edge, while OE and ZZ remain fully asynchronous for immediate output control and power-state transitions.

Burst initiation is dual-path: ADSP triggers processor-initiated bursts with address latching and counter preload, while ADSC enables controller-initiated writes without requiring prior address strobe. Write operations are self-timed and qualified by BWE, BWA/BWB, or GW - supporting byte-level or global writes with automatic I/O tri-state enforcement regardless of OE state.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flat Package (TQFP), JEDEC-standard lead-free, 14 mm × 14 mm body, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous cache SRAM applications.

Compared with IS61LV102418-133TQLI and AS7C31026B-133JCIN, the CY7C1297H-133AXC uniquely combines VDDQ voltage flexibility, asynchronous ZZ sleep, dual-address-strobe support, and hardware-configurable burst order - making it the only option for Pentium-compatible, multi-voltage, low-power cache designs requiring controller co-management.

Availability

CY7C1297H-133AXC is available at Aetrix Electronics and suitable for Intel Pentium-based computing modules, industrial embedded L2 cache subsystems, and network packet buffering applications requiring stable component supply, long-lifecycle availability, and JEDEC-compliant TQFP packaging.

Supply support for CY7C1297H-133AXC 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) is a U.S.-based semiconductor company specializing in memory, PSoC, and programmable solutions for industrial, automotive, and communications markets.

The CY7C1297H belongs to Cypress's high-speed synchronous SRAM product line, engineered specifically for low-latency, burst-capable secondary cache interfacing in x86 and RISC microprocessor systems.

FAQ

What is the function of the MODE pin, and how does it affect burst behavior?

The MODE pin is a static strap input that selects burst order: HIGH (or floating) enables Intel Pentium-style interleaved burst (00→01→10→11), while LOW enables linear burst (00→01→10→11). It must remain stable during operation and is sampled only at power-up or reset. Internal pull-up ensures default interleaved mode if left unconnected.

Can CY7C1297H-133AXC operate with 2.5V I/O while the core runs at 3.3V?

Yes. The device uses separate VDD (3.3V core) and VDDQ (2.5V or 3.3V I/O) supplies. This allows direct connection to 2.5V logic families without level shifters, while maintaining full 133-MHz performance and 6.5 ns tCDV. VDDQ must be stable before VDD during power-up per datasheet sequencing requirements.

How does the ZZ sleep mode interact with ongoing memory accesses?

ZZ is asynchronous: asserting it HIGH forces entry into sleep mode after two clock cycles, but any pending access (e.g., ADSP-initiated read/write) is aborted and not completed. The device must be deselected (CE1/CE2/CE3 inactive) before entering sleep. Recovery requires 2tCYC after ZZ returns LOW, and CEs/ADSP/ADSC must remain inactive during tZZREC.

What distinguishes ADSP from ADSC in burst initiation?

ADSP initiates bursts under processor control: it latches the first address and loads A[1:0] into the burst counter, but write controls (BWE, GW) are ignored in that cycle. ADSC initiates controller-driven writes directly - write signals must be valid on the same cycle, and ADSP must be HIGH. ADSP takes precedence if both are asserted simultaneously.