Renesas 7025S35PFI8

Overview

7025S35PFI8 from IDT is a high-speed 8K × 16 (128 Kbit) true dual-port static RAM with independent asynchronous left/right ports, 35 ns maximum read cycle time, TTL-compatible 5V ±10% supply, and industrial temperature range (–40°C to +85°C). It enables simultaneous reads of the same memory location and supports master/slave cascading for 32-bit+ bus expansion in real-time embedded control systems.

For engineers reviewing the 7025S35PFI8 datasheet, 7025S35PFI8 pinout, 7025S35PFI8 application, or 7025S35PFI8 equivalent, key selection criteria include BUSY arbitration timing (tBAA ≤ 20 ns), semaphore flag support (8 flags via A0–A2), battery backup data retention at 2V, separate upper/lower byte enables (UBL/LBL, UBR/LBR), and compatibility with 84-pin PLCC packaging.

Technical Context

The 7025S35PFI8 implements full hardware port arbitration with on-chip logic that resolves contention via BUSY flag assertion-either address-match or chip-enable triggered-ensuring deterministic access when both ports target the same location. Its dual-port architecture permits fully asynchronous operation: one port can read while the other writes, with no internal synchronization overhead.

It integrates eight semaphore flags accessible via I/O0–I/O15 using A0–A2 addressing and SEM control, enabling inter-processor coordination without external logic. The device supports two power modes: active (typ. 150 mA for 7025S variant) and full standby (typ. 1.0 mA with CMOS-level inputs), with guaranteed 2V data retention in L-version variants-though 7025S35PFI8 is the S (standard-power) grade.

Key Specifications

Pinout & Package

7025S35PFI8 is housed in an 84-pin Plastic Leaded Chip Carrier (PLCC) package with 0.050" lead pitch, body size ≈ 1.15 in × 1.15 in × 0.17 in. Pin 1 is marked by a corner notch; pins are numbered counterclockwise starting from the notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-35AXC and AS7C3256A-35JCIN, the 7025S35PFI8 uniquely delivers true dual-port functionality at 5V in a mature PLCC package-making it optimal for industrial retrofits and systems requiring deterministic arbitration without voltage translation or layout changes.

Availability

7025S35PFI8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data buffers, medical imaging subsystems, test equipment pattern memory, and real-time embedded communication gateways requiring stable component supply across extended product lifecycles.

Supply support for 7025S35PFI8 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) was a fabless semiconductor company specializing in timing, memory interface, RF, and power management ICs before its acquisition by Renesas in 2019. It pioneered high-performance dual-port SRAMs for real-time systems.

The 7025S35PFI8 belongs to IDT's legacy 7025 family of high-speed dual-port SRAMs, designed specifically for deterministic inter-processor communication in industrial automation, defense electronics, and medical instrumentation where concurrent memory access and hardware arbitration are mandatory.

FAQ

What is the maximum operating temperature range for the 7025S35PFI8?

The 7025S35PFI8 is rated for industrial temperature operation from –40°C to +85°C. This specification is confirmed in the "Recommended DC Operating Conditions" table (Table 2683 tbl 05) and applies to all 7025S variants with 'I' suffix in the ordering code, including the PFI8 package variant. It is not qualified for military-grade –55°C to +125°C operation.

Does the 7025S35PFI8 support battery backup data retention?

No, the 7025S35PFI8 does not support battery backup data retention. That feature is exclusive to the 'L' (low-power) version of the 7025 family (e.g., 7025L35PFI8), which specifies 2V data retention current (ICCDR) in Table 2683 tbl 10. The 'S' in 7025S35PFI8 denotes standard power consumption, with standby current specified at 13 mA (ISB1) under TTL input conditions-not µA-level retention mode.

How many semaphore flags does the 7025S35PFI8 provide, and how are they accessed?

The 7025S35PFI8 provides eight hardware semaphore flags. They are accessed via the I/O0–I/O15 data bus using address lines A0–A2 to select the flag index (0–7), with SEM (SEML/SEMR) asserted low and CE high (or UB & LB high) as defined in Truth Table II (2683 tbl 03). This dedicated register is separate from main memory and enables atomic set/clear operations for inter-processor synchronization.

Is the 7025S35PFI8 pin-compatible with other members of the 7025 family?

Yes, the 7025S35PFI8 shares identical pinout and package (84-pin PLCC) with all other 7025S and 7025L variants in the same package type-including 7025S15, 7025S20, and 7025L35. Speed grade (e.g., 35 ns) and power grade (S vs. L) do not affect pin assignment or electrical interface; only AC timing parameters differ. This allows drop-in replacement for timing-margin validation.

What arbitration methods does the 7025S35PFI8 support for resolving port contention?

The 7025S35PFI8 supports two hardware arbitration methods: (1) Address-match arbitration, where BUSY asserts when both ports access the same address, and (2) Chip-enable arbitration, where BUSY activates upon CE assertion on the contending port. Both are governed by tAPS (arbitration priority setup time) of 5 ns minimum, ensuring deterministic resolution without software intervention-as detailed in Tables 2683 tbl 14a/b and Waveforms 2683 drw 15–16.