Renesas 7027S55PFI

Overview

7027S55PFI from IDT (Integrated Device Technology) is a high-speed 32K × 16 dual-port static RAM IC designed for simultaneous, asynchronous access to the same memory location from independent left and right ports. It operates at 55 ns max access time, supports industrial temperature range (–40°C to +85°C), consumes 750 mW active power (typ.), and uses TTL-compatible 5 V ±10% supply. It enables master/slave cascading for 32-bit+ bus expansion in real-time embedded control systems.

For engineers reviewing the 7027S55PFI datasheet, 7027S55PFI pinout, 7027S55PFI application, or 7027S55PFI equivalent, key selection criteria include port arbitration timing (tBDD ≤ 55 ns), BUSY/INT flag behavior under M/S = VIH/VIL configuration, semaphore address mapping (A0–A2), dual-byte enable (UBL/LBR), and TQFP-100 package compatibility with PCB layout constraints for high-density memory subsystems.

Technical Context

The 7027S55PFI implements fully asynchronous dual-port architecture with on-chip hardware arbitration logic that resolves contention via address-match or chip-enable timing. Its BUSY flag asserts on the slave port when the master initiates a write to a shared address, with tBDD = 55 ns max delay before valid read data appears - critical for deterministic inter-processor communication.

It supports two distinct operational modes: as a standalone 512 Kbit dual-port RAM or as a master/slave pair using M/S pin configuration. Semaphore signaling uses dedicated SEM pins and A0–A2 addressing to manage eight shared resource flags across both ports, with tSPS = 5 ns contention window and tSWRD = 5 ns write-to-read latency - enabling low-overhead mutual exclusion in real-time OS kernels.

Key Specifications

Pinout & Package

7027S55PFI is housed in a 100-pin TQFP package with 0.5 mm pitch, body size 14 mm × 14 mm × 1.4 mm. All VCC and GND pins must be connected per datasheet note; package includes dedicated I/O, control, address, and arbitration signal pins for left/right ports.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-55AXC and IDT70V27L15PF, the 7027S55PFI uniquely combines industrial temperature rating, 5 V TTL compatibility, M/S-configurable master/slave operation, and hardware semaphore support - making it the sole option for ruggedized, 5 V-based dual-CPU systems requiring deterministic arbitration.

Availability

7027S55PFI is available at Aetrix Electronics and suitable for real-time inter-processor communication, industrial PLC memory coherency, and digital signal processing buffering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 7027S55PFI 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

IDT (Integrated Device Technology) is a fabless semiconductor company specializing in high-performance timing, memory interface, and RF solutions, now part of Renesas Electronics since 2019.

The IDT7027 family was engineered specifically for deterministic, low-latency dual-processor memory sharing in industrial automation, telecom infrastructure, and test equipment - emphasizing hardware arbitration, semaphore signaling, and industrial-grade reliability.

FAQ

What is the maximum operating temperature range for the 7027S55PFI?

The 7027S55PFI is rated for industrial temperature operation from –40°C to +85°C. This specification is confirmed in the DC Electrical Characteristics table (Table 6) and explicitly stated in the device description on page 2 of the datasheet. The 7027S55PFI maintains full functionality and timing compliance across this entire range without derating, making it suitable for harsh-environment applications such as factory automation controllers and outdoor telecom equipment.

Does the 7027S55PFI support true simultaneous access to the same memory address?

Yes, the 7027S55PFI implements true dual-ported memory cells that allow simultaneous read/write operations to the same memory location. As stated in the Features section on page 1, "True Dual-Ported memory cells which allow simultaneous access of the same memory location." When contention occurs, on-chip arbitration logic uses BUSY flag assertion (tBDD ≤ 55 ns) to stall the later-accessing port, preserving data integrity without external logic.

How does the M/S pin affect BUSY pin behavior on the 7027S55PFI?

When M/S = VIH, the 7027S55PFI operates as a master: BUSYL and BUSYR are push-pull outputs that assert LOW to indicate contention. When M/S = VIL, it operates as a slave: BUSYL and BUSYR become inputs that inhibit writes when driven LOW by a master. This is documented in Note 1 on page 1 and Truth Table V on page 16. The 7027S55PFI's BUSY pins are never open-drain - they are totem-pole outputs in master mode.

What are the valid semaphore address bits for the 7027S55PFI?

The 7027S55PFI uses address lines A0–A2 to select among its eight semaphore flags, as confirmed in Note 1 of Truth Table III (page 4) and Functional Description (page 16). These three bits address semaphores 0–7, and access occurs only when CE = VIH and SEM = VIL - distinct from normal RAM access (CE = VIL, SEM = VIH). No other address bits affect semaphore selection.

Is the 7027S55PFI pin-compatible with other members of the IDT7027 family?

Yes, all IDT7027 variants - including 7027S55PFI, 7027S25PFI, and 7027L20PFI - share identical 100-pin TQFP pinouts and electrical interface definitions, as shown in Pin Configurations (pages 2–3) and Pin Names table (page 3). Differences are limited to speed grade (access time), power profile (S vs L), and temperature grade (commercial vs industrial), not pin function or assignment.