Renesas 70V28L20PFG

Overview

70V28L20PFG from Integrated Device Technology is a high-speed 3.3V 64K × 16 true dual-ported static RAM with independent left/right ports, 20 ns max access time (industrial/commercial), LVTTL-compatible I/O, and on-chip semaphore/arbiter logic for multiprocessor synchronization. It enables simultaneous read/write to the same memory location in systems requiring deterministic inter-processor handshaking.

For engineers reviewing the 70V28L20PFG datasheet, 70V28L20PFG pinout, 70V28L20PFG application, or 70V28L20PFG equivalent, key selection considerations include BUSY arbitration timing (tBAA ≤ 20 ns), dual chip-enable depth expansion, M/S-configurable master/slave operation, and 100-pin TQFP packaging with industrial temperature support (–40°C to +85°C).

Technical Context

The 70V28L20PFG implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses per port. Its hardware arbitration uses push-pull BUSY flags (BUSYL/BUSYR) that assert on address match, with tBDD ≤ 17 ns disable-to-valid-data delay when M/S = VIH.

On-chip semaphore logic provides eight binary latches (addressed via A0–A2) accessible only when CE = VIH and SEM = VIL, enabling token-passing resource locking without software overhead. Interrupt flags (INTL/INTR) are set/cleared by writes to FFFE_H/FFFF_H, supporting mailbox-style inter-processor messaging.

Key Specifications

Pinout & Package

70V28L20PFG is housed in a 100-pin Thin Quad Flatpack (TQFP) with 0.5 mm pitch, 14 mm × 14 mm footprint, and 1.4 mm height. All VCC and GND pins require proper decoupling per datasheet layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1370D-200BAXI and IDT70V36S20PF, the 70V28L20PFG uniquely integrates hardware semaphores and interrupt flags in a 16-bit dual-port configuration, delivering lower-latency inter-processor coordination without external logic or software overhead.

Availability

70V28L20PFG is available at Aetrix Electronics and suitable for real-time multiprocessor control, industrial PLC memory buffering, avionics data concentration, and medical imaging frame storage requiring stable component supply across extended production lifecycles.

Supply support for 70V28L20PFG 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, designs high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 70V28L20PFG belongs to IDT's legacy high-speed dual-port SRAM product line, engineered specifically for deterministic inter-processor communication in safety-critical and real-time embedded systems.

FAQ

What is the maximum operating temperature range for the 70V28L20PFG?

The 70V28L20PFG is rated for industrial temperature operation from –40°C to +85°C. This specification is validated per the Absolute Maximum Ratings table and confirmed in the Recommended DC Operating Conditions section of the datasheet. The device maintains full 20 ns access time performance across this entire range when powered at 3.3V ± 0.3V.

How does the BUSY arbitration logic function in master versus slave mode on the 70V28L20PFG?

In master mode (M/S = VIH), BUSYL and BUSYR are push-pull outputs that assert low when address contention occurs, blocking writes on the contending port. In slave mode (M/S = VIL), BUSYL and BUSYR become inputs that must be held high for normal operation or pulled low to inhibit writes-eliminating the need for external pull-ups. The 70V28L20PFG datasheet specifies both configurations in Truth Table V and Functional Description sections.

Can the 70V28L20PFG be used for depth expansion, and what signals enable this?

Yes, the 70V28L20PFG supports depth expansion using its dual chip-enable inputs (CE0L/CE1L and CE0R/CE1R). When cascading multiple devices, one CE pair per port selects the active unit while the other remains high, placing unused units in standby. This eliminates external decoding logic and maintains full-speed operation across the expanded memory space.

What are the valid address locations for interrupt flag generation in the 70V28L20PFG?

The 70V28L20PFG uses fixed address locations FFFE_H (65534 decimal) to set the left port interrupt flag (INTL) and FFFF_H (65535 decimal) to set the right port interrupt flag (INTR). Setting occurs on write operations with matching CE/OE/R/W conditions per Truth Table IV; clearing is performed by reading those same addresses.

Does the 70V28L20PFG support byte-level write operations, and how are they controlled?

Yes, the 70V28L20PFG supports independent upper- and lower-byte writes via UBL/LBR (left port) and UBR/LBR (right port) signals. When UBL = low and LBL = high, only I/O0–I/O7 are written; when UBL = high and LBL = low, only I/O8–I/O15 are written. This enables compatibility with 8-bit peripherals on a 16-bit bus without data masking in software.