Renesas 70V28L15PFG8

Overview

70V28L15PFG8 from Integrated Device Technology is a high-speed 3.3V 64K × 16 true dual-ported static RAM with independent left/right ports, 15 ns max access time (commercial grade), LVTTL-compatible I/O, and on-chip semaphore/arbiration logic for multiprocessor synchronization. It operates across –40°C to +85°C and supports master/slave cascading for 32-bit+ bus expansion in real-time control systems.

For engineers reviewing the 70V28L15PFG8 datasheet, 70V28L15PFG8 pinout, 70V28L15PFG8 application, or 70V28L15PFG8 equivalent, key selection criteria include simultaneous port arbitration timing (tAPS = 5 ns), BUSY flag behavior under M/S configuration, semaphore write-to-read latency (tSWRD = 5 ns), and dual CE-controlled standby power (ISB3 = 0.2 mA typ).

Technical Context

The 70V28L15PFG8 implements fully asynchronous dual-port architecture with separate address, control, and data buses per port - enabling concurrent read/write to any memory location without internal contention. Its hardware arbitration uses push-pull BUSY outputs (not open-drain) and deterministic priority resolution based on tAPS setup timing.

Semaphore functionality resides in eight dedicated latches (addressed via A0–A2), accessible only when CE = VIH and SEM = VIL, and operates independently of the 64K × 16 RAM array. Interrupt flags (INTL/INTR) are software-triggered via writes to fixed addresses FFFE_H (left) and FFFF_H (right), with no hardware auto-clear.

Key Specifications

Pinout & Package

70V28L15PFG8 is housed in a 100-pin Thin Quad Flatpack (TQFP) with 14 mm × 14 mm body and 1.4 mm height. All GND pins must be connected to ground; all VCC pins require decoupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136-15ZXI and AS7C362000B-15TIN, the 70V28L15PFG8 delivers integrated hardware arbitration and semaphore logic in a single package - reducing system-level design effort, eliminating external logic, and guaranteeing deterministic 5 ns priority resolution for safety-critical real-time applications.

Availability

70V28L15PFG8 is available at Aetrix Electronics and suitable for industrial PLC controllers, avionics data concentrators, and medical imaging subsystems requiring stable component supply across extended product lifecycles.

Supply support for 70V28L15PFG8 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 70V28L15PFG8 belongs to IDT's high-speed dual-port SRAM product line, engineered specifically for deterministic multiprocessor synchronization in real-time embedded systems where software arbitration introduces unacceptable latency.

FAQ

What is the maximum operating frequency supported by the 70V28L15PFG8?

The 70V28L15PFG8 supports a maximum read cycle time (tRC) of 15 ns, enabling reliable operation at 66.7 MHz for non-contention cycles. This assumes proper signal integrity, termination, and adherence to AC timing parameters including tACE (15 ns max chip-enable access) and tAOE (10 ns max output-enable access). The 70V28L15PFG8 does not specify a clock input - its operation is fully asynchronous and governed by control signal timing margins.

How does the BUSY arbitration logic behave when the 70V28L15PFG8 is configured as a slave (M/S = VIL)?

When M/S = VIL, the 70V28L15PFG8 operates in slave mode: BUSYL and BUSYR become inputs that internally inhibit writes when driven LOW. In this configuration, the device relies on an external master to drive BUSY signals - no internal arbitration occurs. The 70V28L15PFG8 datasheet confirms BUSY inputs are used solely for write gating, with no timing specification for tWB (BUSY input to write) beyond 0 ns min.

Can the semaphore flags in the 70V28L15PFG8 be accessed simultaneously by both ports?

No - semaphore access is mutually exclusive. The 70V28L15PFG8 requires CE = VIH and SEM = VIL to activate semaphore mode, and only one port may satisfy this condition at a time due to shared control logic. Attempting concurrent semaphore access triggers undefined behavior per Truth Table III; the device enforces serialization through its internal semaphore state machine, with tSPS = 5 ns contention window ensuring deterministic resolution.

What is the power consumption of the 70V28L15PFG8 in active and standby modes?

The 70V28L15PFG8 draws 145 mA typical dynamic current (ICC) with both ports active at fMAX, and 0.2 mA typical in full CMOS standby (ISB3) when CE inputs are held near rails. Standby current varies by mode: ISB1 = 40 µA (TTL inactive), ISB2 = 90 mA (one port active), and ISB4 = 90 mA (one port in CMOS standby). All values are specified at VCC = 3.3 V and TA = +25°C per datasheet Table 10.

Is the 70V28L15PFG8 pin-compatible with other members of the IDT70V28 family?

Yes - the 70V28L15PFG8 shares identical 100-pin TQFP pinout and signal mapping with 70V28L20PFG8 and 70V28L15PFI, differing only in speed grade and temperature range. All variants support the same CE0/CE1, R/W, OE, BUSY, SEM, and M/S pin functions. However, timing parameters (e.g., tAA = 15 ns vs. 20 ns) and industrial temperature support vary, so design validation is required when substituting speed grades.