Renesas 7028L20PF8

Overview

7028L20PF8 from IDT (Integrated Device Technology) is a high-speed, 64K × 16-bit true dual-ported static RAM with independent left/right ports, 20 ns maximum access time (industrial grade), TTL-compatible 5V ±10% supply, and integrated hardware semaphore/arbiter logic for inter-processor synchronization. It enables simultaneous read/write to the same memory location and supports MASTER/SLAVE cascading for 32-bit+ bus expansion in real-time embedded control systems.

For engineers reviewing the 7028L20PF8 datasheet, 7028L20PF8 pinout, 7028L20PF8 application, or 7028L20PF8 equivalent, key selection criteria include dual-port arbitration timing (tAPS = 5 ns), BUSY flag behavior (push-pull, M/S-configurable), semaphore address mapping (A0–A2), industrial temperature support (–40°C to +85°C), and TQFP-100 package compatibility with 14 mm × 14 mm footprint.

Technical Context

The 7028L20PF8 implements fully asynchronous dual-port operation with separate CE0/CE1, R/W, OE, UB/LB, and SEM controls per port - enabling independent read/write cycles without shared timing constraints. Its on-chip arbitration logic uses address-match detection and M/S-selectable BUSY signaling (push-pull, not open-drain) to resolve contention at the hardware level.

Hardware semaphore functionality operates via dedicated A0–A2-addressed latches (8 flags), accessed only when CE = VIH and SEM = VIL - decoupled from main memory array timing. Interrupt flags (INTL/INTR) are triggered by writes to fixed addresses FFFE_H (left port sets right INTR) and FFFF_H (right port sets left INTL), supporting mailbox-style inter-processor messaging.

Key Specifications

Pinout & Package

7028L20PF8 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 require direct connection; NC pins must remain unconnected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV25 and IDT70V28L25PF, the 7028L20PF8 uniquely delivers 5V TTL compatibility, 20 ns industrial-grade timing, and integrated hardware semaphores in a drop-in TQFP-100 package - making it irreplaceable for maintaining legacy dual-processor systems without board rework.

Availability

7028L20PF8 is available at Aetrix Electronics and suitable for real-time dual-processor control, industrial PLC memory buffering, and communications protocol stack buffering requiring stable component supply across extended product lifecycles.

Supply support for 7028L20PF8 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) is a fabless semiconductor company specializing in high-performance memory, timing, and interconnect solutions for communications, computing, and industrial markets.

The IDT7028 product line was designed specifically for deterministic, low-latency inter-processor communication in dual-CPU embedded systems - emphasizing hardware arbitration, semaphore support, and industrial temperature reliability over generic memory density.

FAQ

What is the maximum operating temperature range supported by the 7028L20PF8?

The 7028L20PF8 is rated for industrial temperature operation from –40°C to +85°C. This specification is confirmed in the "Recommended DC Operating Conditions" table (4836 tbl 03) and applies to all timing parameters including tAA = 20 ns max, tRC = 20 ns, and tAPS = 5 ns. The commercial-grade variant 7028L15 is limited to 0°C to +70°C and is not interchangeable.

How does the M/S pin affect BUSY pin behavior on the 7028L20PF8?

When M/S = VIH, BUSYL and BUSYR operate as push-pull outputs indicating address contention - asserting LOW to stall the contending port. When M/S = VIL, both BUSY pins become inputs used to externally inhibit writes; the internal write-gating logic activates only when BUSY is driven LOW. This dual-mode behavior is documented in Notes 1 and 2 of the Functional Block Diagram and Truth Table V.

Can the 7028L20PF8 perform simultaneous read and write operations on the same memory address?

Yes - the 7028L20PF8 supports true simultaneous read and write to the same memory location. During such operations, the BUSY logic asserts only if both ports attempt writes to the same address. A read/write conflict does not trigger BUSY but may return indeterminate data; the device guarantees correct read data only when the write port has completed its cycle or when BUSY is monitored and respected.

What are the valid address ranges for interrupt flag triggering in the 7028L20PF8?

The 7028L20PF8 uses fixed addresses for interrupt generation: writing to FFFE_H (hex) with CER = R/WR = VIL sets the right-port interrupt flag (INTR), and writing to FFFF_H with CEL = R/WL = VIL sets the left-port flag (INTL). These addresses are reserved for interrupt use only when the interrupt function is enabled; otherwise, they behave as standard SRAM locations.

Is the 7028L20PF8 pin-compatible with other IDT7028 variants such as the 7028L15?

Yes - the 7028L20PF8 shares identical pinout, package (100-pin TQFP), and signal definitions with all IDT7028 family members including 7028L15 and 7028L25. Differences are limited to speed grade (20 ns vs. 15 ns), temperature qualification (industrial vs. commercial), and corresponding AC timing parameters; no PCB layout change is required when substituting within the same package code.