Renesas 7008S25G

Overview

IDT7008S25G from Integrated Device Technology (IDT) is a high-speed 64K × 8 true dual-ported static RAM with independent left/right ports, 25 ns maximum access time (commercial grade), TTL-compatible 5 V ±10% supply, and integrated semaphore/arbitration logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the IDT7008S25G datasheet, IDT7008S25G pinout, IDT7008S25G application, or IDT7008S25G equivalent, key selection considerations include port-to-port contention handling via BUSY flag arbitration, master/slave cascading capability for 16-bit+ data buses, and low-power standby modes (1 mW typ. for IDT7008L variant) - all critical for deterministic multi-CPU memory sharing.

Technical Context

The IDT7008S25G implements fully asynchronous dual-port operation: each port (left/right) has dedicated address (A0–A15), data (I/O0–I/O7), and control lines (CE0/CE1, R/W, OE, SEM, INT, BUSY), enabling simultaneous read/write to the same location without corruption. Its on-chip arbitration logic resolves port conflicts using either address-match or chip-enable timing, with BUSY asserted as push-pull output (master) or input (slave).

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 addresses FFFE_H (left port sets INTR) and FFFF_H (right port sets INTL), enabling mailbox-style inter-processor signaling.

Key Specifications

Pinout & Package

Package: 100-pin TQFP (thin quad flatpack), body size ≈ 14 mm × 14 mm × 1.4 mm; RoHS-compliant, green part option available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-25AC and R1EX24064AS0C-25, the IDT7008S25G uniquely integrates hardware semaphore and BUSY arbitration in a 5 V TTL-native package - making it the only drop-in solution for legacy real-time control systems requiring deterministic, logic-free inter-processor coordination.

Availability

IDT7008S25G is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, and avionics subsystems requiring stable component supply, long-term lifecycle support, and guaranteed commercial-grade timing performance.

Supply support for IDT7008S25G 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) was a fabless semiconductor company specializing in high-performance timing, memory interface, and RF solutions before its acquisition by Renesas in 2019. IDT's dual-port SRAMs were engineered for deterministic real-time systems.

The IDT7008S25G belongs to IDT's high-speed dual-port SRAM product line, designed specifically for multi-processor architectures requiring hardware-synchronized shared memory without software overhead or external arbitration components.

FAQ

What is the maximum operating frequency supported by the IDT7008S25G?

The IDT7008S25G does not operate on a clock signal - it is an asynchronous SRAM. Its speed is defined by access time: 25 ns maximum address access time (tAA) guarantees valid data within 25 ns after address stabilization. This supports effective system timing up to ~40 MHz in tightly controlled read cycles, but actual throughput depends on CE, OE, and R/W timing margins per the AC specifications table.

How does the BUSY arbitration logic work in the IDT7008S25G?

In master mode (M/S = VIH), the IDT7008S25G asserts BUSYL or BUSYR as push-pull outputs when port contention is detected - e.g., both ports attempt access to the same address. The earlier port wins, and the later port's write is inhibited until BUSY deasserts. In slave mode (M/S = VIL), BUSY becomes an input that externally blocks writes, enabling hierarchical arbitration across multiple devices.

Can the IDT7008S25G be used in a 3.3 V system?

No - the IDT7008S25G requires a 5.0 V ±10% supply (4.5 V to 5.5 V) and is TTL-compatible. Its inputs are not 3.3 V tolerant per datasheet absolute maximum ratings (V_TERM = –0.5 V to +7.0 V is stress rating only). For 3.3 V systems, consider Renesas R1EX24064AS0C-25 or level-shifting circuitry.

What is the function of the SEM pin on the IDT7008S25G?

The SEM (semaphore enable) pin selects between RAM and semaphore register access modes. When SEM = VIL and CE = VIH, the device accesses eight internal semaphore flags (addressed by A0–A2) instead of main memory. I/O0 writes the flag value; I/O0–I/O7 read it back. This provides hardware-managed mutual exclusion without CPU intervention.

Does the IDT7008S25G support power-down modes, and how are they activated?

Yes - the IDT7008S25G supports multiple standby modes. Full standby (ISB3 = 0.2 mA typ.) is activated when both CE0 and CE1 per port are held at CMOS-high levels (> V_CC – 0.2 V) and all inputs are stable. Port-specific standby (ISB2) occurs when one port's CE is active (VIL) and the other's is inactive (VIH), reducing current while preserving data integrity.