Renesas 7028L15PFG

Overview

7028L15PFG from IDT (Integrated Device Technology) is a high-speed 64K × 16 true dual-ported static RAM with independent left/right ports, 15 ns max access time (commercial grade), TTL-compatible 5V ±10% supply, and integrated hardware semaphore/arbiter logic for inter-processor synchronization in real-time embedded systems.

For engineers reviewing the 7028L15PFG datasheet, 7028L15PFG pinout, 7028L15PFG application, or 7028L15PFG equivalent, this device supports simultaneous asynchronous reads/writes to shared memory, BUSY-flag arbitration, interrupt signaling via FFFE/FFFF mailbox addresses, and byte-selectable I/O control - critical for deterministic multi-CPU communication in industrial controllers and telecom line cards.

Technical Context

The 7028L15PFG implements fully asynchronous dual-port operation with separate address, data, and control buses per port (A0L–A15L/I/O0L–I/O15L vs A0R–A15R/I/O0R–I/O15R), enabling concurrent memory access without cycle penalties. Its on-chip arbitration logic uses push-pull BUSY outputs (BUSYL/BUSYR) that assert when both ports access the same address, gating writes on the contending side.

Hardware semaphore functionality is implemented via eight dedicated latches addressed by A0–A2 and accessed using CE = VIH / SEM = VIL, allowing atomic token-passing between processors without software overhead. Interrupt flags (INTL/INTR) are set/cleared by writes/reads to fixed addresses FFFE (left) and FFFF (right), supporting mailbox-style inter-processor messaging.

Key Specifications

Pinout & Package

7028L15PFG 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 Note 1–2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1370D-133AXC and AS7C362000B-15JCIN, the 7028L15PFG uniquely integrates true dual-port architecture, hardware semaphores, and BUSY-flag arbitration in a single 5V-compatible package - eliminating external logic and reducing BOM count for deterministic multi-processor memory sharing.

Availability

7028L15PFG is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, avionics flight management units, and medical imaging subsystems requiring stable component supply with long-term lifecycle assurance.

Supply support for 7028L15PFG 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), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and high-performance interconnect solutions for communications, computing, and industrial markets.

The 7028L15PFG 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 requiring hardware-assisted synchronization.

FAQ

What is the maximum operating frequency supported by the 7028L15PFG?

The 7028L15PFG does not operate on a clock signal - it is an asynchronous static RAM. Its performance is defined by access timing parameters: 15 ns maximum address access time (tAA) and 15 ns read cycle time (tRC) under commercial conditions (0°C to +70°C, VCC = 4.5–5.5 V). This enables reliable operation in systems with bus cycles ≥66.7 MHz equivalent bandwidth, but actual throughput depends on system-level bus protocol and control timing margins. The 7028L15PFG achieves this without internal clocking circuitry.

How does the BUSY arbitration logic function in the 7028L15PFG?

In Master mode (M/S = VIH), the 7028L15PFG asserts BUSYL or BUSYR when both ports attempt to access the same memory address simultaneously. The BUSY signal gates the write path on the contending port, preventing corrupted writes. In Slave mode (M/S = VIL), BUSYL/BUSYR become inputs that must be driven externally to inhibit writes - allowing hierarchical arbitration across multiple 7028L15PFG devices in depth-expanded arrays.

Can the 7028L15PFG be used in a 32-bit data bus configuration?

Yes - the 7028L15PFG supports 32-bit expansion via its Master/Slave cascading capability. When two devices are configured with M/S tied high (Master) and low (Slave), their left/right ports can be combined using external logic to form a 64K × 32-bit memory. The 7028L15PFG's dual chip enables (CE0/CE1 per port) and byte-select controls (UBL/LBL, UBR/LBR) ensure synchronized access without added wait states or external arbitration chips.

What are the valid address ranges for interrupt and semaphore functions in the 7028L15PFG?

The 7028L15PFG uses fixed addresses for interrupts: writing to FFFE (hex) sets the left port's INTL flag, and reading FFFE clears it; writing to FFFF sets INTR, and reading FFFF clears it. Semaphores occupy eight locations addressed by A0–A2 (000–111 binary), accessible only when CE = VIH and SEM = VIL - these are separate from the main 64K × 16 memory map and do not consume user memory space.

Is the 7028L15PFG RoHS compliant and what packaging options exist?

Yes, the 7028L15PFG is RoHS-compliant and offered in a green (lead-free) 100-pin TQFP package (package code PFG). The body dimensions are 14 mm × 14 mm × 1.4 mm with 0.5 mm lead pitch. No other package variants (e.g., PGA or BGA) are specified for this speed grade. All VCC and GND pins must be properly decoupled per the manufacturer's layout guidelines to maintain signal integrity and thermal performance.