Renesas 70V24S55PFG8

Overview

70V24S55PFG8 from Integrated Device Technology (IDT) is a high-speed 4K x 16 true dual-port static RAM with independent left/right asynchronous ports, 55 ns maximum read cycle time, 3.3 V single-supply operation, and integrated on-chip semaphore logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the 70V24S55PFG8 datasheet, 70V24S55PFG8 pinout, 70V24S55PFG8 application, or 70V24S55PFG8 equivalent, this device supports simultaneous read/write access to shared memory without external arbitration, delivers low standby current (660 µA typ.), and targets FPGA co-processor buffering, industrial motion controllers, and telecom packet buffering where deterministic latency and bus isolation are critical.

Technical Context

The 70V24S55PFG8 implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port, enabling concurrent access to any memory location. It integrates hardware semaphore flags (8 flags, addressed via A0–A2) with contention resolution logic and BUSY/INT signaling for master/slave coordination.

It operates exclusively from a 3.3 V ±0.3 V supply, uses LVTTL-compatible I/Os, and features automatic power-down via chip enable (CE). The device supports byte-selectable writes (UBL/LBL), full on-chip arbitration, and non-tri-stated push-pull BUSY/INT outputs - all verified for industrial temperature range (−40°C to +85°C).

Key Specifications

Pinout & Package

70V24S55PFG8 is housed in an 84-pin Plastic Leaded Chip Carrier (PLCC, package code PLG84), with dimensions approximately 1.15 in × 1.15 in × 0.17 in. All VDD pins require connection to 3.3 V supply; all VSS pins must be grounded.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-55AXC and IDT70V24L15PF, the 70V24S55PFG8 uniquely balances industrial temperature support, through-hole PLCC compatibility, and hardware M/S cascading - making it optimal for legacy-replacement and mechanically constrained designs where pinout and thermal robustness are prioritized over raw speed.

Availability

70V24S55PFG8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data recorders, and telecom packet buffers requiring stable component supply across extended product lifecycles.

Supply support for 70V24S55PFG8 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, RF, and sensor signal conditioning ICs.

The IDT70V24 family was engineered for deterministic real-time embedded systems requiring hardware-synchronized dual-processor memory sharing - targeting industrial automation, aerospace, and communications infrastructure.

FAQ

What is the maximum operating temperature range for the 70V24S55PFG8?

The 70V24S55PFG8 is rated for industrial temperature operation from −40°C to +85°C, as confirmed in the Absolute Maximum Ratings and Operating Conditions tables of the official IDT datasheet (DSC-5624/10, October 2019). This rating applies to all speed grades within the 70V24S series, including the 55 ns variant.

Does the 70V24S55PFG8 support true simultaneous read/write to the same memory address?

Yes, the 70V24S55PFG8 implements true dual-port SRAM cells that allow simultaneous reads of the same memory location from both ports. Writes to the same address from both ports are resolved via on-chip arbitration, with BUSY flag assertion to indicate contention - a core feature explicitly documented in the Functional Block Diagram and Truth Table I of the 70V24S55PFG8 datasheet.

What is the function of the M/S pin on the 70V24S55PFG8, and how is it used in system design?

The M/S (Master/Slave Select) pin configures the 70V24S55PFG8 for cascaded multi-device operation: when pulled high, it operates as a Master with BUSYR output asserted; when pulled low, it acts as a Slave accepting BUSYR as input. This enables seamless expansion to wider data buses (e.g., 32-bit) without external logic - a capability validated in the "Master/Slave select" section and Pin Names table of the IDT datasheet.

How does the 70V24S55PFG8 implement semaphore functionality, and what are the addressing constraints?

The 70V24S55PFG8 provides eight hardware semaphore flags accessed via I/O0 (write) and all I/O lines (read), with addressing controlled by A0–A2. Semaphore mode requires CE = VIH or UB & LB = VIH plus SEM = VIL - distinct from standard RAM access. This dual-mode operation (RAM vs. semaphore) is defined in Truth Table II and AC Electrical Characteristics notes for tSAA and tSOP parameters in the official datasheet.

Is the 70V24S55PFG8 pin-compatible with other members of the IDT70V24 family, such as the 70V24S15 or 70V24L55?

No - while all IDT70V24 variants share the same 84-pin PLCC (PLG84) package and pinout, speed grade suffixes (e.g., '15', '55') denote different internal timing characteristics and power profiles. The 70V24S55PFG8 is not a drop-in replacement for faster or lower-power variants due to guaranteed access time differences (55 ns vs. 15 ns) and standby current divergence (660 µA vs. 3.3 mW active), as specified in Tables 09b and 09c of the datasheet.