Renesas 70V38L15PFG8

Overview

70V38L15PFG8 from IDT (now Renesas) is a high-speed, 3.3V, 64K × 18 true dual-port static RAM with independent left/right ports, 15 ns max access time (commercial grade), LVTTL-compatible I/O, and integrated hardware semaphore/arbiter logic for inter-processor synchronization in real-time embedded systems.

For engineers reviewing the 70V38L15PFG8 datasheet, 70V38L15PFG8 pinout, 70V38L15PFG8 application, or 70V38L15PFG8 equivalent, key selection considerations include simultaneous dual-port read/write capability, BUSY-flag arbitration timing (tBAA ≤ 15 ns), M/S-configurable master/slave operation, and 100-pin TQFP packaging for high-density PCB layouts.

Technical Context

The 70V38L15PFG8 implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses per port-enabling concurrent, collision-free access to any memory location. Its on-chip arbitration logic uses push-pull BUSY outputs (not open-drain) and supports both address-match and CE-controlled BUSY assertion modes.

Hardware semaphore functionality operates via dedicated A0–A2-addressed latches (8 flags), accessed using CE = VIH / SEM = VIL, with tSOP = 10 ns pulse width guarantee and tSPS = 5 ns contention window. Interrupt flags (INTL/INTR) are triggered by writes to FFFE_H (left) or FFFF_H (right), supporting mailbox-style inter-processor messaging without software polling.

Key Specifications

Pinout & Package

70V38L15PFG8 is housed in a 100-pin Thin Quad Flatpack (TQFP) with 0.5 mm pitch, 14 mm × 14 mm body, and exposed thermal pad (not electrically connected). Pin 1 is located at top-left corner (marking dot adjacent), with pins numbered counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1370D-133AXC and AS7C362000B-15JCIN, the 70V38L15PFG8 uniquely integrates hardware semaphore, BUSY arbitration, and interrupt mailbox logic in a compact 100-pin TQFP - reducing BOM count and eliminating timing-critical external glue logic for tightly coupled dual-processor systems.

Availability

70V38L15PFG8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data concentrators, and medical imaging pipelines requiring stable component supply, long-term lifecycle support, and guaranteed commercial-grade timing performance.

Supply support for 70V38L15PFG8 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

Renesas Electronics (formerly IDT) is a global semiconductor leader specializing in high-performance timing, memory, and embedded processing solutions for industrial, automotive, and communications infrastructure.

The 70V38L15PFG8 belongs to IDT's legacy high-speed dual-port SRAM product line, engineered specifically for deterministic, low-latency inter-processor communication in real-time embedded systems where hardware-assisted synchronization is critical.

FAQ

What is the maximum operating frequency supported by the 70V38L15PFG8?

The 70V38L15PFG8 is specified with a 15 ns maximum access time (tAA), enabling reliable operation at up to 67 MHz in commercial temperature range (0°C to +70°C). This timing applies to asynchronous read cycles; actual system frequency depends on board layout, signal integrity, and control timing margins. The 70V38L15PFG8 does not require a clock input, so its effective throughput is determined by external controller timing compliance with tRC (15 ns read cycle time) and tWC (15 ns write cycle time).

How does the BUSY arbitration logic function in master vs. slave mode on the 70V38L15PFG8?

In master mode (M/S = VIH), BUSYL and BUSYR are push-pull outputs that assert LOW when address contention occurs - stalling the contending port's write until resolution. In slave mode (M/S = VIL), BUSYL and BUSYR become inputs that must be driven HIGH externally to permit writes; tying them LOW disables writes entirely. The 70V38L15PFG8's BUSY logic is self-contained and requires no external pull-ups, unlike open-drain alternatives.

Can the 70V38L15PFG8 be used for depth expansion without external logic?

Yes - the 70V38L15PFG8 supports depth expansion using dual chip enables (CE0L/CE1L and CE0R/CE1R) per port. When cascading multiple devices, asserting CE0 on one device and CE1 on another enables seamless 128K×18 or larger configurations without additional decoding logic. The 70V38L15PFG8's internal arbitration remains functional across expanded arrays, though external AND gates are required to combine BUSY signals from multiple devices.

What are the valid voltage levels for the 70V38L15PFG8's input pins?

The 70V38L15PFG8 accepts LVTTL-compatible input levels: VIH ≥ 2.0 V (up to VCC + 0.3 V) and VIL ≤ 0.8 V (down to –0.3 V). Input leakage is limited to ±5 µA across the full operating range. All inputs tolerate 3.6 V absolute maximum, but sustained operation above VCC + 0.3 V violates recommended conditions and may impact reliability. The 70V38L15PFG8 does not include internal clamping diodes to VCC or GND.

How are the semaphore flags accessed and controlled on the 70V38L15PFG8?

Semaphore flags are accessed by setting CE = VIH and SEM = VIL, then addressing A0–A2 (3 bits = 8 flags). Writes occur on I/O0 only; reads return the flag value on all I/O0–I/O17 lines. Timing is governed by tSOP (10 ns min pulse width) and tSPS (5 ns contention window). The 70V38L15PFG8's semaphore logic operates independently of the main RAM array and retains state during CE-driven standby modes.