Cypress Semiconductor Corp CY7C1345G-100AXI

Overview

CY7C1345G-100AXI from Cypress Semiconductor is a 4-Mbit (128K × 36) flow-through synchronous SRAM with 3.3 V core supply, 2.5/3.3 V I/O supply, 8.0 ns clock-to-output delay at 100 MHz, and user-selectable Intel Pentium–compatible interleaved or linear burst sequences. It serves as secondary cache memory for high-speed microprocessors requiring glueless interface, low-latency burst reads/writes, and synchronous self-timed writes.

For engineers reviewing the CY7C1345G-100AXI datasheet, CY7C1345G-100AXI pinout, CY7C1345G-100AXI application, or CY7C1345G-100AXI equivalent, key selection criteria include burst mode control via MODE pin, ZZ sleep mode implementation, byte-write granularity (BWA–BWD), synchronous address strobes (ADSP/ADSC), and TQFP-100 package compatibility with JEDEC JESD8-5 I/O standards.

Technical Context

The CY7C1345G-100AXI implements a 2-bit on-chip wrap-around burst counter fed by A[1:0], enabling automatic address increment during burst cycles controlled by ADV. All synchronous inputs-including addresses, CE1/CE2/CE3, ADSP/ADSC, BWx, BWE, GW, and MODE-are registered on the rising edge of CLK.

Asynchronous OE enables tristate control of bidirectional DQ/DQP I/Os, while ZZ (Pin 64) must be externally tied to ground per errata. The device supports both processor-initiated (ADSP) and controller-initiated (ADSC) burst accesses, with ADSP taking priority when both strobes are active.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flat Package (TQFP), 14 × 20 × 1.4 mm, lead-free (RoHS-compliant), with exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61LV51236A-100TQLI and AS7C3256A-10JC, the CY7C1345G-100AXI uniquely delivers Pentium-compatible interleaved burst, dual-address-strobe arbitration, and hardware-configurable MODE selection-enabling drop-in replacement in legacy x86 cache designs without redesigning timing or control logic.

Availability

CY7C1345G-100AXI is available at Aetrix Electronics and suitable for high-speed CPU cache modules, network switching buffers, industrial motion controllers, and avionics data acquisition systems requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for CY7C1345G-100AXI 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 fabless semiconductor company specializing in memory, microcontrollers, and programmable logic solutions for embedded and industrial applications.

The CY7C1345G belongs to Cypress's high-speed synchronous SRAM product line, designed specifically for secondary cache implementations in x86 and compatible microprocessor systems requiring glueless interface, burst efficiency, and deterministic timing.

FAQ

What is the correct connection for the ZZ pin on CY7C1345G-100AXI?

The ZZ pin (Pin 64) must be externally connected to ground, as specified in the Rev. *P errata (page 22). Leaving it floating or pulling it HIGH violates functional specification and may cause unpredictable sleep-mode behavior or data retention failure. The device includes an internal pull-down, but external grounding is mandatory for guaranteed operation.

Can CY7C1345G-100AXI operate with 2.5 V VDDQ while using 3.3 V VDD?

Yes. The device supports independent core and I/O supplies: VDD must be 3.3 V ± 0.3 V, while VDDQ accepts either 2.5 V ± 0.2 V or 3.3 V ± 0.3 V. This allows direct interfacing with 2.5 V processor buses without level shifters, provided VSSQ is referenced to the same ground as VSS and noise margins are verified per AC characteristics tables.

How does the MODE pin affect burst address sequencing?

The MODE pin determines burst order at initialization: HIGH selects interleaved (0→2→4→6→1→3→5→7), matching Intel Pentium processors; LOW selects linear (0→1→2→3→4→5→6→7). It is a static strap pin - changing its state mid-operation causes undefined burst behavior and must be held stable throughout device operation.

What happens if both ADSP and ADSC are asserted simultaneously?

ADSP takes unconditional priority over ADSC. When both are LOW, only ADSP is recognized - the address is latched, A[1:0] loads the burst counter, and ADSC is ignored. This priority scheme ensures deterministic behavior in systems where both CPU and cache controller could issue requests, preventing race conditions in address capture.