Renesas 70V28L25PF8

Overview

70V28L25PF8 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 grade), LVTTL-compatible I/O, and on-chip semaphore/arbiration logic for multi-processor synchronization. It operates across –40°C to +85°C and supports simultaneous read/write to the same memory location in master/slave configurations.

For engineers reviewing the 70V28L25PF8 datasheet, 70V28L25PF8 pinout, 70V28L25PF8 application, or 70V28L25PF8 equivalent, key selection criteria include dual-port arbitration timing (tBDD ≤ 17 ns), BUSY flag push-pull output behavior, 100-pin TQFP package compatibility, and support for 32-bit bus expansion via M/S cascading.

Technical Context

The 70V28L25PF8 implements fully asynchronous dual-port operation with separate address, control, and data buses per port - enabling concurrent access without internal clocking. Its hardware arbitration uses address-match detection and M/S-configurable BUSY signaling (push-pull, not open-drain) to resolve contention at the cell level.

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

Key Specifications

Pinout & Package

70V28L25PF8 is housed in a 100-pin Thin Quad Flatpack (TQFP) with exposed pad thermal design. Pin 1 is located at top-left corner (A1), with GND and VCC distributed across four corners and center rows for noise suppression and power integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-20AXC and AS7C36256PFS-20, the 70V28L25PF8 uniquely integrates arbitration, semaphore, and interrupt logic in silicon - reducing system-level complexity, eliminating external glue logic, and guaranteeing sub-20 ns contention resolution without software intervention.

Availability

70V28L25PF8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data concentrators, medical imaging pipelines, automotive ADAS fusion units, and real-time test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 70V28L25PF8 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 70V28L25PF8 belongs to IDT's high-speed dual-port SRAM product line, engineered specifically for deterministic multi-processor synchronization in real-time embedded systems where hardware-enforced resource arbitration is critical.

FAQ

What is the maximum operating temperature range supported by the 70V28L25PF8?

The 70V28L25PF8 is qualified for industrial temperature operation from –40°C to +85°C. This rating is verified per JEDEC JESD22-A104 and applies across full voltage (3.0V–3.6V) and timing specifications - including 20 ns access time and BUSY arbitration timing (tBDD ≤ 17 ns). The device uses CMOS process technology optimized for thermal stability in enclosed control cabinets and vehicle ECUs.

How does the BUSY signal behave when the 70V28L25PF8 is configured as a slave?

When M/S = VIL, the 70V28L25PF8 operates in slave mode: BUSYL and BUSYR become dedicated write-inhibit inputs (not outputs). A low signal on either BUSY pin blocks writes to that port regardless of R/W state. This allows external arbitration logic to directly gate memory access - and eliminates need for pull-up resistors since internal circuitry interprets the pin as a control input, not an open-drain signal.

Can the 70V28L25PF8 be used to expand data bus width beyond 16 bits?

Yes - the 70V25PF8 supports 32-bit or wider bus expansion using master/slave cascading. When multiple 70V28L25PF8 devices are connected with M/S pins tied appropriately, the master device coordinates BUSY arbitration across the array while slave devices respond to centralized control. No external logic is needed for depth or width expansion, and full-speed operation is maintained per IDT application note AN-4849.

What memory locations are reserved for interrupt functionality in the 70V28L25PF8?

The 70V28L25PF8 reserves two addresses for hardware interrupts: FFFE_H triggers INTL (left port interrupt) when written by the right port, and FFFF_H triggers INTR (right port interrupt) when written by the left port. These locations function as user-defined mailboxes - the 16-bit data written is preserved and readable by the receiving port. If unused, they operate as standard SRAM locations.

Does the 70V28L25PF8 require external pull-up resistors on BUSY or interrupt pins?

No - the 70V28L25PF8 features push-pull BUSY outputs (when M/S = VIH) and open-collector compatible interrupt flags (INTL/INTR). BUSY pins drive actively high/low without external components; interrupt pins default to high-impedance and require only a single external pull-up per signal for wired-OR interrupt aggregation - confirmed in DC Electrical Characteristics Table 9 and Functional Block Diagram.