Renesas 709279L12PFI8

Overview

709279L12PFI8 from IDT is a high-speed 32K × 16-bit synchronous dual-port static RAM with true dual-ported memory cells enabling simultaneous access to the same address from both ports, 12ns max clock-to-data access in pipelined mode, industrial temperature range (–40°C to +85°C), and TTL-compatible 5V ±10% supply. It serves in real-time interprocessor communication and FPGA co-processor buffering.

For engineers reviewing the 709279L12PFI8 datasheet, 709279L12PFI8 pinout, 709279L12PFI8 application, or 709279L12PFI8 equivalent, key selection criteria include pipelined vs. flow-through output timing, dual chip enable depth expansion capability, counter-enabled burst addressing, and industrial-grade standby power (1mW typ.) under CE-controlled power-down.

Technical Context

The device implements fully synchronous operation on both left and right ports with 4ns setup/1ns hold on all inputs, registered address/data/control paths, and self-timed write for minimal cycle time. Its dual independent clock domains (CLKL/CLKR) support asynchronous port coordination without external arbitration logic.

It features configurable output modes via FT/PIPE pin: pipelined (9ns tCD2, 15ns tCYC2, 67MHz) or flow-through (25ns tCYC1), plus separate upper-byte (UB/LB) and lower-byte (UBL/LBR) controls for multiplexed bus compatibility and byte-selective read/write operations.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flatpack (TQFP), 14mm × 14mm × 1.4mm body, lead-free (Green) compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-15AXC and IDT70V9279L12PF, the 709279L12PFI8 uniquely delivers 5V-native operation with 1mW industrial standby and dual CE depth expansion - making it optimal for retrofitting or maintaining existing 5V industrial control systems without voltage conversion.

Availability

709279L12PFI8 is available at Aetrix Electronics and suitable for real-time interprocessor communication, FPGA co-processor buffering, and industrial PLC memory expansion requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 709279L12PFI8 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 timing, memory interface, RF, and high-performance silicon solutions for communications, computing, and industrial markets.

The IDT709279 family was designed for deterministic, low-latency shared memory in tightly coupled multi-processor systems - emphasizing simultaneous access, industrial reliability, and seamless depth/width scalability without external logic.

FAQ

What is the maximum operating frequency of the 709279L12PFI8 in pipelined mode?

The 709279L12PFI8 supports up to 67MHz operation in pipelined output mode, derived from its 15ns maximum clock cycle time (tCYC2). This is validated across the industrial temperature range (–40°C to +85°C) with 5V ±10% supply. The device achieves this using registered inputs and self-timed write, ensuring timing closure without external wait-state generation. The 709279L12PFI8 maintains this frequency under full-load conditions with proper PCB layout and termination.

Does the 709279L12PFI8 support independent clock domains for left and right ports?

Yes, the 709279L12PFI8 has fully independent clock inputs: CLKL for the left port and CLKR for the right port. Each port operates synchronously on its respective rising clock edge, with no internal phase alignment requirement. This enables true asynchronous operation between processors or logic domains - for example, an ARM core running at 100MHz can communicate with an FPGA logic block clocked at 75MHz via the 709279L12PFI8 without clock domain crossing circuitry.

How does the address counter function in the 709279L12PFI8, and what pins control it?

The 709279L12PFI8 integrates a programmable address counter per port, controlled by CNTENL/CNTRSTL (left) and CNTENR/CNTRSTR (right). When CNTENX = L on a rising CLK, the internal address increments automatically; CNTRSTX = L resets it to A0. ADSX remains active to latch external addresses when needed. This allows burst transfers without CPU address bus updates - a key feature used in DMA engines interfacing with the 709279L12PFI8 for high-efficiency data movement.

What is the standby current specification for the 709279L12PFI8, and how is it achieved?

The 709279L12PFI8 achieves 1mW typical standby power (ISB3), corresponding to ~200µA at 5V, by disabling internal circuitry when both CE0X = VIH and CE1X = VIH (or CE0X > VCC–0.2V and CE1X < 0.2V). This "full standby" mode powers down registers, drivers, and array bias - verified across the industrial temperature range. Unlike simpler SRAMs, the 709279L12PFI8 maintains data retention in this state, making it suitable for battery-backed or energy-harvesting applications where memory state must persist during sleep.

Can the 709279L12PFI8 be used for depth expansion, and what signals are required?

Yes, the 709279L12PFI8 supports depth expansion using only its dual chip enables (CE0X/CE1X per port) - no external logic gates are needed. For two devices, one uses CE0L = L/CE1L = H while the other uses CE0L = H/CE1L = L on the same port; address lines connect in parallel. This configuration is explicitly documented in Truth Table I and Figure 4 of the datasheet. The 709279L12PFI8's CE architecture ensures clean deselection and avoids bus contention during expansion - a critical advantage over single-CE dual-port alternatives.