Renesas 70V28L15PF8

Overview

70V28L15PF8 from Integrated Device Technology (IDT) is a high-speed, 3.3V, 64K × 16 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. It enables simultaneous read/write to the same memory location in real-time inter-processor communication systems such as industrial PLCs and telecom line cards.

For engineers reviewing the 70V28L15PF8 datasheet, 70V28L15PF8 pinout, 70V28L15PF8 application, or 70V28L15PF8 equivalent, key selection considerations include its master/slave cascading capability for 32-bit+ bus expansion, BUSY-flag arbitration timing (tBAA ≤ 15 ns), and dual-chip-enable depth expansion without external logic.

Technical Context

The 70V28L15PF8 implements fully asynchronous dual-port architecture with separate address, control, and data buses per port - enabling concurrent access without internal synchronization overhead. Its on-chip arbitration logic resolves contention via push-pull BUSY flags (BUSYL/BUSYR), with tBDD ≤ 15 ns propagation delay from write to valid read data under master mode (M/S = VIH).

Hardware semaphore support uses dedicated A0–A2-addressed latches (8 flags) accessible via SEM = VIL, CE = VIH, allowing atomic token-passing between processors. Interrupt signaling is implemented via fixed mailbox addresses FFFE_H (INTL set) and FFFF_H (INTR set), with tINS/tINR ≤ 20 ns timing.

Key Specifications

Pinout & Package

70V28L15PF8 is housed 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 layout guidelines to ensure signal integrity and thermal stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-15ZXI and IS61WV6416BLL-15MLI, the 70V28L15PF8 uniquely integrates master/slave cascading, push-pull BUSY signaling, and on-chip semaphores - delivering complete hardware arbitration in a single device for tightly coupled multi-processor systems.

Availability

70V28L15PF8 is available at Aetrix Electronics and suitable for industrial PLC backplanes, telecom line cards, medical imaging subsystems, and automotive ADAS sensor fusion hubs requiring stable component supply and long-term production continuity.

Supply support for 70V28L15PF8 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), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, and RF solutions for high-performance computing and communications infrastructure.

The 70V28L15PF8 belongs to IDT's high-speed dual-port SRAM product line, designed specifically for deterministic, low-latency inter-processor communication in real-time embedded systems requiring hardware-coordinated shared memory.

FAQ

What is the maximum operating frequency supported by the 70V28L15PF8?

The 70V28L15PF8 does not operate on a clock signal - it is an asynchronous SRAM. Its 15 ns access time (tAA) supports effective bus operation up to approximately 66 MHz in systems where address and control setup/hold times are met. The actual achievable data rate depends on system-level timing margins, not an internal clock. This makes the 70V28L15PF8 ideal for interfacing with microcontrollers, FPGAs, and DSPs that use asynchronous memory protocols.

How does the BUSY arbitration logic work in the 70V28L15PF8?

In master mode (M/S = VIH), the 70V28L15PF8 asserts BUSYL or BUSYR when both ports attempt to access the same memory address simultaneously. The BUSY signal is a push-pull output that stalls the contending port's write operation internally - no external logic is needed. The arbitration priority is determined by which port's address and enable signals stabilize first, with tAPS = 5 ns minimum setup time required to guarantee deterministic resolution. In slave mode (M/S = VIL), BUSY becomes a write-inhibit input.

Can the 70V28L15PF8 be used in a 32-bit data bus configuration?

Yes - the 70V28L15PF8 supports 32-bit expansion via master/slave cascading. One device operates as master (M/S = VIH), the other as slave (M/S = VIL); their BUSY and interrupt signals are interconnected to coordinate access. The dual chip-enable inputs (CE0/CE1) per port eliminate need for external decoding logic. This configuration maintains full 15 ns access speed across the combined 32-bit width, as confirmed in IDT Application Note AN-4849.

What are the voltage and current requirements for reliable operation of the 70V28L15PF8?

The 70V28L15PF8 requires a single 3.3 V ± 0.3 V supply (VCC = 3.0 V to 3.6 V) with all VCC and GND pins properly decoupled. Typical active current is 145 mA (both ports active), and standby current drops to 0.2 mA in full CMOS standby mode (ISB3). Input levels follow LVTTL thresholds: VIH ≥ 2.0 V, VIL ≤ 0.8 V. These specifications ensure compatibility with standard 3.3 V logic families without level shifters.

How are the semaphore flags accessed and used in the 70V28L15PF8?

The 70V28L15PF8 includes eight dedicated semaphore latches addressed by A0–A2. To access them, SEM must be low (VIL) and CE high (VIH) - placing the device in semaphore mode. Writing to I/O0 sets/clears the flag; reading returns the value across all 16 I/O lines. These flags enable atomic token-passing between processors - for example, one CPU writes "0" to claim a resource, and the other reads the flag before attempting access. This mechanism avoids race conditions without software overhead.