Renesas 70V28L20PFI8

Overview

70V28L20PFI8 from IDT (Integrated Device Technology) is a high-speed, 3.3V, 64K × 16 true dual-port static RAM with independent left/right ports, 20 ns max access time, industrial temperature range (–40°C to +85°C), and integrated hardware semaphore/arbiter logic for multiprocessor synchronization. It enables simultaneous read/write access to the same memory location in real-time embedded control systems.

For engineers reviewing the 70V28L20PFI8 datasheet, 70V28L20PFI8 pinout, 70V28L20PFI8 application, or 70V28L20PFI8 equivalent, key selection criteria include port-to-port arbitration timing (tAPS = 5 ns), BUSY flag behavior under M/S = VIH/VIL modes, semaphore write-to-read latency (tSWRD = 5 ns), and LVTTL-compatible 3.3V ±0.3V operation with 100-pin TQFP packaging.

Technical Context

The 70V28L20PFI8 implements fully asynchronous dual-port architecture with separate address, data, and control buses per port-no shared timing constraints between left (L) and right (R) sides. Its on-chip arbitration logic uses address-match detection and M/S pin configuration to determine whether BUSY signals operate as push-pull outputs (Master) or write-inhibit inputs (Slave).

Hardware semaphore functionality resides in eight dedicated latches (addressed by A0–A2), accessible only when CE = VIH and SEM = VIL, and supports token-passing allocation without software overhead. Interrupt flags (INTL/INTR) are triggered by writes to fixed addresses FFFE_H (left sets right flag) and FFFF_H (right sets left flag), enabling mailbox-style interprocessor communication.

Key Specifications

Pinout & Package

70V28L20PFI8 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; NC pins are not internally bonded.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-20AXC and IS61WV6416BLL-20NLI, the 70V28L20PFI8 uniquely integrates hardware semaphore arbitration and configurable BUSY logic in a 3.3V package - eliminating external components and guaranteeing deterministic sub-25 ns conflict resolution essential for safety-critical embedded systems.

Availability

70V28L20PFI8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data concentrators, and medical imaging subsystems requiring stable component supply across extended product lifecycles.

Supply support for 70V28L20PFI8 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) was a fabless semiconductor company specializing in high-performance timing, memory interface, and RF solutions before its acquisition by Renesas Electronics in 2019.

The 70V28L20PFI8 belongs to IDT's high-speed dual-port SRAM product line, designed specifically for deterministic, low-latency interprocessor communication in real-time embedded systems requiring hardware-enforced resource arbitration.

FAQ

What is the maximum operating temperature range for the 70V28L20PFI8?

The 70V28L20PFI8 is rated for industrial temperature operation from –40°C to +85°C. This specification is validated per Absolute Maximum Ratings and DC Electrical Characteristics tables in the official datasheet (DSC-4849/8, June 2019). The device maintains full 20 ns access time performance across this entire range, making it suitable for harsh-environment applications such as factory automation and transportation systems.

How does the M/S pin affect BUSY signal behavior in the 70V28L20PFI8?

When M/S = VIH, the 70V28L20PFI8 operates as a Master: BUSYL and BUSYR become push-pull outputs that assert low upon address match to indicate port contention. When M/S = VIL, it operates as a Slave: BUSYL and BUSYR become inputs that internally inhibit writes when driven low. This dual-mode behavior allows flexible system-level arbitration topologies without external logic.

Can the 70V28L20PFI8 support byte-wide writes without affecting adjacent data?

Yes. The 70V28L20PFI8 supports independent upper-byte (UB/UBR) and lower-byte (LB/LBR) write enables per port. When only UBL or LBL is asserted low (with R/WL low and CE0L low), only the corresponding 8-bit lane is written - leaving the opposite byte unchanged. This is confirmed in Truth Table II and enables precise metadata updates in shared memory buffers.

What addresses trigger the interrupt flags INTL and INTR in the 70V28L20PFI8?

The 70V28L20PFI8 uses fixed addresses to control interrupts: writing to FFFE_H (hex) with CER = R/WR = VIL sets the right-port interrupt flag (INTR), while reading FFFE_H with CEL = OEL = VIL clears it. Similarly, writing to FFFF_H sets INTL, and reading FFFF_H clears INTL. These are defined in Truth Table IV and require no configuration registers.

Is the 70V28L20PFI8 pin-compatible with earlier speed grades like 70V28L15?

Yes. The 70V28L20PFI8 shares identical pinout, package (100-pin TQFP), and functional block diagram with the 70V28L15 family. The only difference is guaranteed access time: 20 ns max (vs. 15 ns for L15). All control, address, I/O, and arbitration pins map one-to-one - enabling drop-in replacement where timing margins permit.