Renesas 7028L15PFI8

Overview

7028L15PFI8 from IDT (Integrated Device Technology) is a high-speed, TTL-compatible, 64K × 16 dual-ported static RAM with independent left/right ports, 15 ns max access time (commercial grade), 5 V ±10% single supply, and integrated hardware semaphore/arbiter logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the 7028L15PFI8 datasheet, 7028L15PFI8 pinout, 7028L15PFI8 application, or 7028L15PFI8 equivalent, this page delivers verified timing specs, master/slave arbitration behavior, BUSY/INT signal semantics, true dual-port conflict resolution, and industrial-grade thermal validation - all critical for deterministic multi-CPU memory sharing designs.

Technical Context

The 7028L15PFI8 implements fully asynchronous dual-port operation with separate address, control, and I/O buses per port, enabling simultaneous read/write to the same memory location only when using semaphore-protected access. Its on-chip arbitration logic uses push-pull BUSY outputs (not open-drain) and supports both master (M/S = VIH) and slave (M/S = VIL) configurations for scalable memory expansion.

Hardware semaphore functionality operates via dedicated A0–A2-addressed latches accessible through CE = VIH / SEM = VIL, allowing atomic token-passing between processors without software polling. Interrupt flags (INTL/INTR) are triggered by writes to FFFE_H (left port sets right flag) and FFFF_H (right port sets left flag), with user-defined 16-bit payload storage at those addresses.

Key Specifications

Pinout & Package

7028L15PFI8 is housed in a 100-pin Thin Quad Flatpack (TQFP) with 0.5 mm pitch, 14 mm × 14 mm body size, and exposed thermal pad (per IDT package code PNG100). All VCC and GND pins must be individually decoupled per datasheet Note 1–2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-15ZXI and IS61LV6416-15TQLI, the 7028L15PFI8 uniquely delivers native 5 V TTL compatibility, integrated master/slave arbitration, and hardware semaphores - eliminating level shifters, external logic, and software mutexes required by alternatives.

Availability

7028L15PFI8 is available at Aetrix Electronics and suitable for real-time industrial PLCs, multi-core DSP co-processing, avionics flight control systems, and medical imaging data pipelines requiring stable component supply, long-lifecycle support, and guaranteed commercial-grade timing performance.

Supply support for 7028L15PFI8 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 interface, and RF solutions before its acquisition by Renesas Electronics in 2019. It pioneered industry-standard dual-port SRAM architectures.

The 7028L15PFI8 belongs to IDT's legacy high-speed dual-port SRAM product line, engineered specifically for deterministic, low-latency inter-processor communication in mission-critical embedded systems where hardware-enforced coherency is mandatory.

FAQ

What is the maximum operating temperature range supported by the 7028L15PFI8?

The 7028L15PFI8 is rated for commercial temperature operation only: 0°C to +70°C. This is explicitly defined by the '15' speed grade and confirmed in datasheet Table 10 and Section 2 ("Industrial and Commercial Temperature Ranges"). The industrial-grade variant is 7028L20PFI8 (–40°C to +85°C), not the 7028L15PFI8.

Does the 7028L15PFI8 support true simultaneous read/write to the same memory address?

No - the 7028L15PFI8 permits simultaneous reads to the same location, but simultaneous writes to identical addresses trigger BUSY arbitration. When both ports attempt a write to the same address, the BUSY signal asserts on the losing port, gating its write pulse. Only one write completes; the other is inhibited. This behavior is documented in Truth Table V and the "Busy Logic" section.

How are the interrupt flags (INTL and INTR) configured and cleared on the 7028L15PFI8?

INTL is asserted when the right port writes to address FFFE_H (with CER = R/WR = VIL); it is cleared when the left port reads FFFE_H (CEL = OEL = VIL). INTR is asserted when the left port writes to FFFF_H; it is cleared when the right port reads FFFF_H. Both flags retain state until explicitly cleared - no auto-clear or timeout. This is specified in Truth Table IV and the Functional Description section.

Can the 7028L15PFI8 be used in a 32-bit data bus configuration?

Yes - the 7028L15PFI8 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 signals are externally ANDed, and address/data buses are aligned. This configuration is explicitly described in the "Description" section and Figure 1 of the datasheet as enabling "32-bit-or-more word systems" without discrete logic.

What is the function of the SEM pin on the 7028L15PFI8, and how does it differ from CE?

The SEM pin enables access to the eight hardware semaphore latches (addressed by A0–A2) when CE = VIH. When SEM = VIL, the device enters semaphore mode - RAM access is disabled, and I/O0 drives the latch value while all I/Os reflect it. CE controls RAM power and access; SEM controls functional mode (RAM vs. semaphore). This separation is defined in Truth Table III and the "Semaphores" section.