Renesas 7008S55PF

Overview

7008S55PF from IDT (Integrated Device Technology) is a high-speed 64K × 8 true dual-ported static RAM with independent left/right ports, 55 ns maximum access time (commercial grade), TTL-compatible 5 V ±10% supply, and integrated port arbitration logic. It enables simultaneous asynchronous reads from both ports to the same memory location and supports MASTER/SLAVE cascading for 16-bit-or-wider data bus expansion in real-time embedded control systems.

For engineers reviewing the 7008S55PF datasheet, 7008S55PF pinout, 7008S55PF application, or 7008S55PF equivalent, this device delivers deterministic BUSY-flag arbitration, on-chip semaphore signaling, interrupt flag generation via mailbox addresses FFFE/FFFF, and low-power standby modes - critical for multi-processor communication, motion controller buffer sharing, and industrial PLC I/O coherency.

Technical Context

The 7008S55PF implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses per port. Its on-chip arbitration logic resolves contention using either address-match detection or CE-controlled timing, asserting BUSY outputs (push-pull, non-tri-state) to inhibit writes during conflict.

It supports two distinct memory access modes: standard RAM access (CE = VIL, SEM = VIH) and semaphore register access (CE = VIH, SEM = VIL), where eight semaphore flags are addressed by A0–A2 and written via I/O0. Interrupts are triggered by writes to fixed mailbox addresses (FFFE for INTL, FFFF for INTR), with configurable clear logic per port.

Key Specifications

Pinout & Package

7008S55PF 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 pins require connection to 5 V supply; all GND pins must be tied to ground.

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 7008S55PF uniquely integrates push-pull BUSY/INT, M/S-selectable cascading, and on-chip semaphores - reducing BOM count, PCB area, and real-time OS overhead in tightly coupled multi-processor systems.

Availability

7008S55PF is available at Aetrix Electronics and suitable for industrial motion controllers, multi-core PLCs, and avionics display systems requiring stable component supply, long-term lifecycle assurance, and guaranteed commercial-grade timing performance.

Supply support for 7008S55PF 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 high-performance timing, memory, and interface solutions before its acquisition by Renesas Electronics in 2019.

The IDT7008 product line was designed specifically for deterministic, low-latency inter-processor communication in real-time embedded systems - emphasizing hardware arbitration, dual-port concurrency, and seamless bus expansion.

FAQ

What is the maximum operating frequency supported by the 7008S55PF?

The 7008S55PF does not operate on a clock signal - it is a fully asynchronous static RAM. Its maximum effective throughput is governed by the 55 ns read cycle time (tRC), enabling up to ~18.2 MHz sustained random-access bandwidth when interfaced with appropriately timed control logic. No external clock is required or used.

Does the 7008S55PF support simultaneous write operations to the same memory address from both ports?

No. The 7008S55PF prohibits simultaneous writes to the same address via hardware arbitration: when address match or CE overlap occurs, the BUSY flag asserts to inhibit the later-arriving write. Only simultaneous reads to the same location are permitted - writes must be serialized either by software coordination or hardware BUSY handshake.

How is the interrupt function implemented in the 7008S55PF?

The 7008S55PF implements mailbox-style interrupts: writing to address FFFF (HEX) on the left port asserts INTR (right port flag), and writing to FFFE asserts INTL (left port flag). Clearing is asymmetric - INTL clears on read of FFFE with OEL/CEL active; INTR clears on read of FFFF. Both flags are push-pull outputs.

What is the role of the M/S pin on the 7008S55PF?

The M/S pin configures the 7008S55PF as Master (M/S = VIH) or Slave (M/S = VIL). In Master mode, BUSYL/BUSYR are outputs that signal contention to other devices. In Slave mode, they become inputs that accept BUSY from a Master to gate local writes - enabling hierarchical arbitration in multi-device 16-bit+ memory systems.

Can the 7008S55PF be used in industrial temperature applications?

No. The 7008S55PF is rated for commercial temperature range only (0°C to +70°C). For industrial operation (–40°C to +85°C), IDT offered the 7008L20PF and 7008L25PF variants - the 'S' suffix and '55' speed grade in 7008S55PF explicitly denote commercial-grade timing and thermal specification.