Renesas 7008S55PFI

Overview

7008S55PFI from IDT is a high-speed 64K × 8 true dual-port static RAM with independent left/right ports, 55 ns max access time (commercial grade), TTL-compatible 5 V ±10% supply, and integrated port arbitration logic. It enables simultaneous read/write access to the same memory location and supports master/slave cascading for 16-bit+ data bus expansion in real-time embedded control systems.

For engineers reviewing the 7008S55PFI datasheet, 7008S55PFI pinout, 7008S55PFI application, or 7008S55PFI equivalent, key selection considerations include BUSY/INT flag timing (tBDD ≤ 55 ns, tINS ≤ 40 ns), dual CE-controlled power-down modes (ISB3 ≤ 5 mA), semaphore address mapping (A0–A2), and industrial-grade TQFP-100 packaging with –40°C to +85°C operation.

Technical Context

The 7008S55PFI implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port-no shared timing constraints between left (L) and right (R) sides. Its on-chip arbitration logic resolves contention via push-pull BUSY flags (BUSYL/BUSYR) and supports both address-match and CE-controlled BUSY assertion with tAPS = 5 ns setup guarantee.

It integrates dedicated semaphore registers (8 flags, addressed by A0–A2) accessible only when CE = VIH and SEM = VIL, enabling inter-processor synchronization without external logic. Interrupts are triggered by writes to fixed mailbox addresses (FFFE_H for INTL, FFFF_H for INTR), with tINR ≤ 40 ns reset timing and non-tri-state totem-pole outputs.

Key Specifications

Pinout & Package

7008S55PFI is packaged in a 100-pin Thin Quad Flatpack (TQFP) with 0.5 mm pitch, body size ≈ 14 mm × 14 mm × 1.4 mm. All VCC and GND pins must be connected per datasheet Notes 1 and 4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136-55JC and AS7C364B-55PC, the 7008S55PFI delivers integrated hardware arbitration, deterministic semaphore timing (tSPS = 5 ns), and configurable master/slave operation-reducing BOM count by up to 3 discrete logic ICs and eliminating arbitration firmware overhead.

Availability

7008S55PFI is available at Aetrix Electronics and suitable for real-time industrial PLCs, avionics health monitors, and medical imaging data pipelines requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 7008S55PFI 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, and interface solutions for communications, computing, and industrial markets.

The 7008S55PFI belongs to IDT's legacy dual-port SRAM product line, designed specifically for deterministic inter-processor communication in hard real-time systems where hardware-enforced synchronization and low-latency memory access are mandatory.

FAQ

What is the maximum operating temperature range certified for the 7008S55PFI?

The 7008S55PFI is specified for industrial operation from –40°C to +85°C. This range is validated across all AC and DC electrical parameters including tAA ≤ 55 ns, ISB3 ≤ 5 mA, and BUSY arbitration timing (tAPS = 5 ns). Commercial-grade variants (e.g., 7008S55PF) are rated 0°C to +70°C only.

Does the 7008S55PFI support true simultaneous read operations from both ports to the same memory address?

Yes, the 7008S55PFI uses true dual-port SRAM cells that permit concurrent reads from identical addresses on left and right ports without contention or timing penalty. This capability is inherent to the cell architecture-not dependent on external logic-and is confirmed in the Functional Description section of the datasheet.

How is semaphore functionality implemented in the 7008S55PFI, and what address range does it occupy?

The 7008S55PFI implements eight hardware semaphore flags accessed via A0–A2 when CE = VIH and SEM = VIL. These flags reside in a dedicated register bank-not main memory-and are written via I/O0 and read across all I/O0–I/O7 lines. They occupy no address space in the 64K × 8 array.

What are the power-down current specifications for the 7008S55PFI in full standby mode?

In full standby mode (ISB3), where both ports have CMOS-level inputs (CE > VCC − 0.2 V, all inputs < 0.2 V or > VCC − 0.2 V), the 7008S55PFI draws ≤ 5 mA. This is measured at VCC = 5.5 V and TA = +25°C per Table 10b and applies across the full industrial temperature range.

Can the 7008S55PFI be configured as a slave device, and how does BUSY behave in that mode?

Yes, setting M/S = VIL configures the 7008S55PFI as a slave. In this mode, BUSYL and BUSYR become inputs (not outputs), and an external master's BUSY signal inhibits writes to the slave port. The slave does not assert BUSY; it responds only to incoming BUSY assertions per Truth Table V and Figure 13.