Renesas 70V27S55PF

Overview

70V27S55PF from Integrated Device Technology is a high-speed 3.3V 32K × 16 dual-port static RAM with true simultaneous access to the same memory location from independent left and right ports, 55 ns maximum read cycle time (tRC), LVTTL-compatible I/O, and on-chip semaphore/arbiter logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the 70V27S55PF datasheet, 70V27S55PF pinout, 70V27S55PF application, or 70V27S55PF equivalent, this page delivers verified timing parameters, master/slave BUSY arbitration behavior, byte-selectable write control, industrial temperature support (–40°C to +85°C), and TQFP-100 package layout - all critical for deterministic multi-CPU memory sharing designs.

Technical Context

The 70V27S55PF implements fully asynchronous dual-port architecture with separate address, control, and bidirectional data buses per port, enabling concurrent read/write operations without external synchronization logic. Its on-chip arbitration logic resolves contention via address-match or chip-enable priority, with BUSY flag assertion (push-pull) when M/S = VIH (Master mode).

It supports semaphore signaling across ports using dedicated SEM pins and A0–A2-addressed flags, with guaranteed tSPS (semaphore contention window) ≤ 5 ns and tSWRD (write-to-read delay) ≤ 5 ns. Power management includes four standby modes (ISB1–ISB4), with full CMOS-level standby current as low as 0.2 mA for the IDT70V27S variant.

Key Specifications

Pinout & Package

70V27S55PF is housed in a 100-pin TQFP (PN100-1) with 0.5 mm pitch, requiring standard SMT reflow profile. All VDD (pins 26, 50, 75, 99) and VSS (pins 1, 25, 51, 76, 100) must be decoupled locally; NC pins (e.g., pins 7, 8, 17, 18, 32, 33, 42, 43, 57, 58, 67, 68, 82, 83, 92, 93) must remain unconnected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-55AXC and R1EX24032AS0C-55#U0, the 70V27S55PF uniquely integrates arbitration, semaphore, and Master/Slave expansion in a single 100-pin TQFP - reducing PCB layers, eliminating glue logic, and guaranteeing sub-55 ns contention resolution without firmware intervention.

Availability

70V27S55PF is available at Aetrix Electronics and suitable for industrial automation controllers, avionics data concentrators, and medical imaging subsystems requiring stable component supply, long-lifecycle support, and guaranteed industrial temperature performance.

Supply support for 70V27S55PF 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

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

The IDT70V27S/L product line was engineered specifically for deterministic multi-processor memory sharing in real-time embedded systems - emphasizing hardware arbitration, low-latency semaphore signaling, and seamless 32-bit+ bus expansion without external logic.

FAQ

What is the maximum operating frequency supported by the 70V27S55PF?

The 70V27S55PF does not operate at a fixed clock frequency; it is an asynchronous SRAM. Its maximum effective throughput is determined by its 55 ns read cycle time (tRC), supporting up to ~18.2 MHz continuous random access. Actual system bandwidth depends on address stability, CE/OE timing, and bus turnaround - not a synchronous clock input.

Does the 70V27S55PF support both Master and Slave configurations simultaneously?

No - the 70V27S55PF operates exclusively as either Master or Slave, selected by the logic level on the M/S pin. When M/S = VIH, BUSYL and BUSYR are push-pull outputs used for arbitration; when M/S = VIL, they become inputs that inhibit writes during contention. A single device cannot function as both roles concurrently.

How does the 70V27S55PF handle simultaneous writes to the same memory address from both ports?

The 70V27S55PF uses hardware arbitration: if both ports attempt a write to the same address, the port whose address/control signals stabilize first (per tAPS setup time) wins. The losing port's BUSY signal asserts (if Master) or is sampled (if Slave), blocking its write. No data corruption occurs - the memory cell retains the winning port's value.

Can the 70V27S55PF be used in a 3.3 V-only system without level shifters?

Yes - the 70V27S55PF is fully LVTTL-compatible with VDD = 3.3 V ± 0.3 V and VIH minimum of 2.0 V. All inputs accept 3.3 V logic levels directly; outputs drive to VOH ≥ 2.4 V at –4 mA, ensuring interoperability with standard 3.3 V microcontrollers, FPGAs, and ASICs without translation.

What is the purpose of the two chip enable pins (CE0 and CE1) per port on the 70V27S55PF?

CE0 and CE1 provide hierarchical port control: CE1 enables the port's control logic (including arbitration and semaphore), while CE0 gates the memory array itself. Holding CE1 = VIH and CE0 = VIL places the port in low-power standby (ISB2/ISB4), retaining data but disabling array access - critical for dynamic power gating in battery-operated systems.