Renesas 7024S35PFI8

Overview

7024S35PFI8 from IDT is a high-speed 4K × 16 true dual-port static RAM with independent left/right ports, 35 ns max read cycle time, TTL-compatible 5V ±10% supply, and industrial temperature range (–40°C to +85°C). It supports simultaneous asynchronous access, on-chip semaphore arbitration, and battery-backed data retention down to 2V - enabling use in real-time dual-CPU communication buffers and military-grade avionics memory subsystems.

For engineers reviewing the 7024S35PFI8 datasheet, 7024S35PFI8 pinout, 7024S35PFI8 application, or 7024S35PFI8 equivalent, this page delivers verified electrical specs, validated pin functions for the 84-pin PLCC package, confirmed dual-port arbitration behavior, and two field-deployed alternative parts with documented functional trade-offs in timing, power, and temperature grading.

Technical Context

The 7024S35PFI8 implements fully asynchronous dual-port operation with separate address, control, and I/O buses per port - allowing concurrent reads/writes to any memory location without external logic. Its on-chip arbitration logic resolves port contention via BUSY flag signaling and master/slave configuration (M/S pin), while integrated semaphore registers (A0–A2 addressed) enable inter-processor synchronization without software overhead.

It features separate upper-byte (UB/UBR) and lower-byte (LB/LBR) enables for multiplexed bus compatibility, full TTL-level I/O compatibility, and automatic power-down when chip enables (CEL/CER) are deasserted. The "S" suffix denotes standard-power operation (750 mW active, 5 mW standby), and the "35" specifies 35 ns maximum access time across the industrial temperature range.

Key Specifications

Pinout & Package

7024S35PFI8 is packaged in an 84-pin Plastic Leaded Chip Carrier (PLCC), body size ≈ 1.15 in × 1.15 in × 0.17 in, with gull-wing leads and JEDEC-standard pinout. All VCC pins require decoupling; all GND pins must be connected to system ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-35AXC and AS7C34096B-35TIN, the 7024S35PFI8 uniquely combines industrial temperature rating, on-chip BUSY arbitration, and 2V data retention in the 84-pin PLCC form factor - making it the sole option for ruggedized dual-CPU designs requiring guaranteed hardware-coordinated access and brown-out resilience.

Availability

7024S35PFI8 is available at Aetrix Electronics and suitable for industrial PLC memory buffers, aerospace avionics data exchange, and military radar signal processing requiring stable component supply across extended lifecycle programs.

Supply support for 7024S35PFI8 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 IDT7024 family was designed specifically for deterministic, low-latency inter-processor communication in dual-CPU and real-time embedded systems - emphasizing hardware arbitration, byte-select flexibility, and robust environmental operation.

FAQ

What is the maximum operating frequency supported by the 7024S35PFI8?

The 7024S35PFI8 does not operate on a clock signal - it is a fully asynchronous static RAM. Its performance is defined by timing parameters such as tRC (read cycle time) and tAA (address access time), both specified at 35 ns maximum under industrial conditions. This enables reliable operation in systems with bus toggle rates up to approximately 28.5 MHz (1/35 ns), assuming proper setup/hold margins and load capacitance.

Does the 7024S35PFI8 support battery backup, and what voltage is required?

Yes, the 7024S35PFI8 supports battery backup operation with data retention down to 2.0 V (VDR), as confirmed in Table 10 of the datasheet. When VCC drops below 2.0 V, the device enters data retention mode with ICCDR ≤ 4000 µA (military/industrial grade), preserving memory contents without external refresh - a key feature for mission-critical systems experiencing power interruption.

How does the BUSY arbitration mechanism work on the 7024S35PFI8?

The 7024S35PFI8 uses the M/S pin to configure master/slave roles: when M/S = H, BUSY is an output flag asserting within 35 ns (tBAA) if the opposite port initiates a conflicting write to the same address; when M/S = L, BUSY is an input that must be sampled before initiating a write. This hardware-enforced flow control prevents data corruption without CPU polling or software locks - a core differentiator versus single-port or software-arbitrated alternatives.

Can the 7024S35PFI8 be used in a 32-bit data bus configuration?

Yes - the 7024S35PFI8 supports 32-bit expansion via master/slave cascading. Two devices can be connected with M/S = H (master) and M/S = L (slave), sharing address and control lines while using separate I/O buses. The master's BUSY output connects to the slave's BUSY input, enabling coordinated arbitration across the combined 32-bit word - eliminating need for external glue logic as stated in the product description.

What is the purpose of the SEM (semaphore) pins on the 7024S35PFI8?

The SEML and SEMR pins enable access to eight dedicated 1-bit semaphore flags stored in on-chip registers. These are addressed using A0–A2 and read/written via I/O0 (write) and all I/O lines (read). They provide hardware-accelerated mutual exclusion for shared resources - for example, allowing one CPU to lock a memory region before writing, while the other polls the flag via INTR - reducing inter-processor synchronization latency to nanoseconds instead of milliseconds.