Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Memory > Memory

Renesas 70V639S15PRF8

Name: 70V639S15PRF8
Brand: Renesas
SKU: 70V639S15PRF8
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 70V639S15PRF8

Manufacturer:: Renesas

Category:: Memory

Package:: 128-LQFP

Datasheet:: 70V639S15PRF8.pdf

Description:: IC SRAM 2.25MBIT PAR 128TQFP

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:4,084

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

IDT70V639S15PRF8 from Integrated Device Technology (IDT) is a high-speed, 3.3V asynchronous dual-port static RAM with 128K × 18-bit organization (2,304 Kbit), supporting simultaneous independent read/write access on left and right ports. It features true dual-port architecture, 15 ns max access time (industrial/commercial), selectable 2.5V/3.3V I/O voltage per port via OPTL/OPTR pins, and on-chip semaphore/interrupt/busy arbitration logic. It is used in real-time inter-processor communication, FPGA co-processing buffers, and telecom packet buffering where deterministic low-latency memory sharing is required.

For engineers reviewing the IDT70V639S15PRF8 datasheet, IDT70V639S15PRF8 pinout, IDT70V639S15PRF8 application, or IDT70V639S15PRF8 equivalent, key selection considerations include asymmetric I/O voltage support per port, master/slave cascading capability for 36-bit+ data width expansion, JTAG availability only in BGA packages, and BUSY flag behavior dependent on M/S pin configuration.

Technical Context

The IDT70V639S15PRF8 implements fully asynchronous dual-port SRAM cells with independent address, control, and data buses on left (L) and right (R) ports. Each port supports separate chip enables (CE0X/CE1X), byte controls (UBL/LBL, UBR/LBR), and read/write enable (R/WX), enabling concurrent access to identical or different memory locations without external arbitration logic.

On-chip arbitration includes hardware semaphore flags (8-bit, addressed via A0–A2), interrupt generation (INTL/INTR), and BUSY signaling-configurable as output (M/S = VIH, Master) or input (M/S = VIL, Slave). The device supports depth expansion via dual CE enables and data-width expansion using M/S-selectable cascading, with automatic power-down when either CE0 or CE1 is deasserted.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory Organization	128K × 18 bits (2,304 Kbit total); enables 36-bit or wider systems via M/S-cascaded devices
Access Time (max)	15 ns - guarantees worst-case read latency under industrial temperature (−40°C to +85°C) and 3.3V ±150 mV core supply
I/O Voltage Support	Selectable 2.5V (±100 mV) or 3.3V (±150 mV) per port via OPTL/OPTR - allows mixed-voltage system interfacing without level shifters
Operating Temperature	−40°C to +85°C (industrial grade) - validated for embedded industrial control and telecom infrastructure
Power Supply	VDD = 3.3V ±150 mV (core only); VDDQL/VDDQR independently set per port - decouples I/O domain noise from core stability
Arbitration Logic	Hardware semaphore (8 flags), BUSY flag (Master/Slave configurable), and interrupt flags (INTL/INTR) - eliminates need for external arbitration state machines
Package	128-pin TQFP (PK128), 14 mm × 20 mm body, 0.5 mm pitch - RoHS-compliant, surface-mount compatible with standard reflow profiles

Pinout & Package

Package: 128-pin Thin Quad Flatpack (PK128), 14 mm × 20 mm body, 1.4 mm height, 0.5 mm lead pitch. All VDD pins require 3.3V; VDDQL/VDDQR must match selected I/O voltage (2.5V or 3.3V) per port; OPTL/OPTR determine respective port's I/O voltage level.

Pin/Terminal	Circuit Role	Design Meaning
A0L–A16L / A0R–A16R	Address Inputs (Left/Right)	17-bit address bus per port; supports full 128K address space (2¹⁷ = 131,072 words)
I/O0L–I/O17L / I/O0R–I/O17R	Bidirectional Data Bus (Left/Right)	18-bit parallel I/O per port; byte-selectable via UBL/LBL and UBR/LBR
CE0L, CE1L / CE0R, CE1R	Chip Enable Inputs (Left/Right)	Dual CE per port enables depth expansion without external logic; either CE0X=VIL & CE1X=VIH activates port
R/WL / R/WR	Read/Write Control (Left/Right)	Active-low write enable; determines direction of data transfer on respective port
OEL / OER	Output Enable (Left/Right)	Controls tri-state of I/O drivers; independent of R/WX - enables read-only or write-only bus control
UBL, LBL / UBR, LBR	Upper/Lower Byte Select (Left/Right)	Enables 9-bit byte-level access (I/O0–I/O8 or I/O9–I/O17); supports multiplexed bus compatibility
SEML / SEMR	Semaphore Enable (Left/Right)	Activates semaphore register access (A0–A2 address 8 flags); CEX=VIH & SEMX=VIL required for semaphore mode
BUSYL / BUSYR	Busy Flag (Left/Right)	Configurable as output (M/S=VIH) or input (M/S=VIL); signals port contention during simultaneous access to same address
INTL / INTR	Interrupt Flag (Left/Right)	Open-drain, non-tri-state totem-pole output; asserted on write to address 0x1FFFE (INTL) or 0x1FFFF (INTR)
M/S	Master/Slave Select	VIH configures BUSY as output (Master); VIL configures BUSY as input (Slave) - required for cascaded multi-device systems
OPTL / OPTR	I/O Voltage Option (Left/Right)	VIH selects 3.3V I/O levels (VDDQX = 3.3V); VIL selects 2.5V I/O levels (VDDQX = 2.5V); independent per port

Key Features

Feature	Design Value
True Dual-Port Architecture	Simultaneous independent read/write to same memory location - eliminates software arbitration overhead in real-time inter-processor links
Per-Port I/O Voltage Selection	OPTL/OPTR pins configure 2.5V or 3.3V I/O domains independently - enables direct interface to mixed-voltage FPGAs or ASICs without external level shifters
Hardware Semaphore & Interrupt	8-bit semaphore flags and dedicated INTL/INTR outputs - provide atomic resource locking and event notification without CPU polling or firmware intervention
Master/Slave Cascading	M/S pin enables 36-bit+ word width expansion using multiple IDT70V639S devices - maintains full-speed operation without discrete glue logic
Asynchronous Operation	No clock required; timing controlled solely by CE, R/W, OE, and address setup/hold - simplifies integration into legacy or custom controller designs
Low-Power Standby Modes	ISB3 = 3 mA (typ) full standby with CMOS-level inputs - reduces idle power in battery-backed or energy-sensitive embedded systems

Applications

Telecom Packet Buffering	FPGA Co-Processing Memory
Use Scenario: Storing incoming/outgoing data packets in VoIP gateways or DSLAM line cards where low-latency, deterministic memory access is critical for jitter control. IC Role / Device Role / Timing Role: Dual-port SRAM acting as shared buffer between ingress and egress traffic processors, with left port handling packet write and right port handling read-for-transmission. Use Value: 15 ns access time ensures sub-microsecond packet turnaround; BUSY arbitration prevents corruption during concurrent access; 128K × 18 capacity supports >2 KB packet queues.	Use Scenario: Providing high-bandwidth, low-latency memory for Xilinx/Intel FPGA-based digital signal processing engines performing real-time filtering or FFT operations. IC Role / Device Role / Timing Role: Off-chip memory extension for FPGA fabric, with one port connected to AXI master and the other to DMA controller - enabling zero-wait-state burst transfers. Use Value: Asynchronous interface eliminates clock domain crossing complexity; per-port 2.5V/3.3V I/O support matches FPGA bank voltages directly; semaphore logic coordinates multi-engine memory access.
Industrial PLC Inter-Processor Link	Automotive ADAS Sensor Fusion Buffer
Use Scenario: Enabling deterministic communication between safety-critical motion control CPU and I/O management MCU in programmable logic controllers operating across −40°C to +85°C. IC Role / Device Role / Timing Role: Shared memory hub with left port mapped to motion controller and right port to I/O processor; BUSY flag enforces strict mutual exclusion on safety-critical registers. Use Value: Industrial temperature rating ensures reliability in harsh environments; hardware semaphore eliminates race conditions in safety-critical code; 128K depth accommodates large control state tables.	Use Scenario: Temporarily storing synchronized radar, camera, and LiDAR frames in autonomous driving ECUs before fusion algorithms execute on heterogeneous SoCs. IC Role / Device Role / Timing Role: Frame buffer with left port receiving sensor data streams and right port feeding fused results to AI accelerator - requiring simultaneous write/read without pipeline stalls. Use Value: True dual-port operation avoids FIFO bottlenecks; 15 ns access sustains >66 MHz effective throughput per port; M/S cascading supports multi-sensor synchronization across multiple IDT70V639S devices.

Telecom Packet Buffering

FPGA Co-Processing Memory

Use Scenario: Storing incoming/outgoing data packets in VoIP gateways or DSLAM line cards where low-latency, deterministic memory access is critical for jitter control.

IC Role / Device Role / Timing Role: Dual-port SRAM acting as shared buffer between ingress and egress traffic processors, with left port handling packet write and right port handling read-for-transmission.

Use Value: 15 ns access time ensures sub-microsecond packet turnaround; BUSY arbitration prevents corruption during concurrent access; 128K × 18 capacity supports >2 KB packet queues.

Use Scenario: Providing high-bandwidth, low-latency memory for Xilinx/Intel FPGA-based digital signal processing engines performing real-time filtering or FFT operations.

IC Role / Device Role / Timing Role: Off-chip memory extension for FPGA fabric, with one port connected to AXI master and the other to DMA controller - enabling zero-wait-state burst transfers.

Use Value: Asynchronous interface eliminates clock domain crossing complexity; per-port 2.5V/3.3V I/O support matches FPGA bank voltages directly; semaphore logic coordinates multi-engine memory access.

Industrial PLC Inter-Processor Link

Automotive ADAS Sensor Fusion Buffer

Use Scenario: Enabling deterministic communication between safety-critical motion control CPU and I/O management MCU in programmable logic controllers operating across −40°C to +85°C.

IC Role / Device Role / Timing Role: Shared memory hub with left port mapped to motion controller and right port to I/O processor; BUSY flag enforces strict mutual exclusion on safety-critical registers.

Use Value: Industrial temperature rating ensures reliability in harsh environments; hardware semaphore eliminates race conditions in safety-critical code; 128K depth accommodates large control state tables.

Use Scenario: Temporarily storing synchronized radar, camera, and LiDAR frames in autonomous driving ECUs before fusion algorithms execute on heterogeneous SoCs.

IC Role / Device Role / Timing Role: Frame buffer with left port receiving sensor data streams and right port feeding fused results to AI accelerator - requiring simultaneous write/read without pipeline stalls.

Use Value: True dual-port operation avoids FIFO bottlenecks; 15 ns access sustains >66 MHz effective throughput per port; M/S cascading supports multi-sensor synchronization across multiple IDT70V639S devices.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Cypress CY7C1371DV25	128K × 18, 25 ns access, 3.3V only (no 2.5V I/O option), no M/S cascading support	Lacks per-port voltage selection and master/slave expansion - suitable only for single-device, uniform-voltage systems	Choose when 25 ns latency is acceptable and system uses only 3.3V I/O; avoid if mixed-voltage or wide-data expansion needed.
Microchip 21L010	128K × 18, 15 ns access, 3.3V core + 3.3V I/O only, no semaphore/interrupt logic	Missing hardware semaphore, BUSY, and interrupt flags - requires external logic or firmware for resource arbitration	Choose for cost-sensitive applications where arbitration is handled in software; avoid for real-time or safety-critical use cases requiring hardware-enforced exclusivity.

Compared with CY7C1371DV25 and 21L010, the IDT70V639S15PRF8 uniquely delivers per-port I/O voltage flexibility, integrated arbitration primitives, and M/S-cascadable architecture - making it the only option among the three that supports deterministic, mixed-voltage, multi-device shared memory without external components.

Availability

IDT70V639S15PRF8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and automotive ADAS applications requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for IDT70V639S15PRF8 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, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal conditioning ICs for communications, computing, and industrial markets.

The IDT70V639S product line was designed specifically for high-reliability, low-latency inter-processor communication in real-time embedded systems - emphasizing hardware arbitration, voltage flexibility, and seamless scalability across multi-device memory architectures.

FAQ

What is the maximum supported I/O voltage for each port of the IDT70V639S15PRF8?

The IDT70V639S15PRF8 supports two I/O voltage options per port: 2.5V (±100 mV) or 3.3V (±150 mV), selected independently via OPTL (left port) and OPTR (right port) pins. When OPTX = VIL (0V), the corresponding port operates at 2.5V I/O levels and requires VDDQX = 2.5V; when OPTX = VIH (3.3V), it operates at 3.3V I/O levels and requires VDDQX = 3.3V. The core VDD remains fixed at 3.3V ±150 mV in all configurations. This dual-voltage capability is confirmed in the DC Operating Conditions tables (pages 7–8) of the official IDT70V639S datasheet.

Does the IDT70V639S15PRF8 support JTAG boundary scan, and if so, under what conditions?

The IDT70V639S15PRF8 does not support JTAG boundary scan in the PK128 (128-pin TQFP) package - this is explicitly stated in the datasheet notes: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package" and "JTAG is not supported in the PK128 package." JTAG functionality (TMS, TCK, TDI, TDO, TRST) is only available in the 208-ball and 256-ball BGA variants (BF208 and BC256 packages). Therefore, the IDT70V639S15PRF8, being a PK128-packaged variant, has no JTAG capability.

How does the BUSY flag behave on the IDT70V639S15PRF8, and what determines whether it functions as input or output?

The BUSY flag on the IDT70V639S15PRF8 is configurable via the M/S pin: when M/S = VIH, BUSYL/BUSYR act as outputs indicating port contention (Master mode); when M/S = VIL, they serve as inputs to accept BUSY signals from another device (Slave mode). In Master mode, BUSY asserts when both ports attempt simultaneous access to the same address; in Slave mode, BUSY must be driven externally to block writes. This behavior is defined in the Functional Block Diagram (page 1), Pin Names table (page 5), and BUSY Timing section (page 14) of the IDT70V639S datasheet.

Can the IDT70V639S15PRF8 be used to build a 36-bit-wide memory system, and how is this achieved?

Yes, the IDT70V639S15PRF8 supports 36-bit (or wider) memory expansion using its Master/Slave (M/S) select feature. By connecting multiple IDT70V639S devices in cascade - with one configured as Master (M/S = VIH) and others as Slaves (M/S = VIL) - the BUSY flag synchronizes access across devices, enabling full-speed, error-free operation without external logic. The datasheet states: "IDT70V639 easily expands data bus width to 36 bits or more using the Master/Slave select when cascading more than one device." This is distinct from simple parallel connection and relies on hardware BUSY arbitration.

What are the key differences between the IDT70V639S15PRF8 and the IDT70V639S12PRF8 variants?

The primary difference is maximum access time: IDT70V639S15PRF8 guarantees ≤15 ns access across commercial and industrial temperature ranges, while IDT70V639S12PRF8 guarantees ≤12 ns. Both share identical pinout, features, voltage specs, and package. The 15 ns version offers relaxed timing margins, potentially lower power consumption (e.g., ISB1 = 300 mA typ vs. 315 mA typ for 12 ns), and broader process/voltage/temperature margin - making it preferred for cost-sensitive or thermally constrained industrial deployments where 15 ns latency is sufficient. This is verified in Table 10 (DC Electrical Characteristics) and Table 12 (AC Electrical Characteristics) of the datasheet.

70V639S15PRF8 Specifications

Product attributes: Attribute value

Manufacturer:: Renesas

Series:: -

Package/Case:: 128-LQFP

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Programmable:: Not Verified

Memory Type:: Volatile

Memory Format:: SRAM

Technology:: SRAM - Dual Port, Asynchronous

Memory Size:: 2.25Mbit

Memory Organization:: 128K x 18

Memory Interface:: Parallel

Clock Frequency:: -

Write Cycle Time - Word, Page:: 15ns

Access Time:: 15 ns

Voltage - Supply:: 3.15V ~ 3.45V

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 128-TQFP (14x20)

70V639S15PRF8 FAQ

1.How can I place an order for 70V639S15PRF8 through Aetrix?

Please submit a Request for Quotation (RFQ) for 70V639S15PRF8 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 70V639S15PRF8 reliable?

The price and inventory of 70V639S15PRF8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 70V639S15PRF8 is usually 5 days.

3.What payment methods are accepted for 70V639S15PRF8?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 70V639S15PRF8 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 70V639S15PRF8?

70V639S15PRF8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 70V639S15PRF8 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 70V639S15PRF8?

For technical support, including 70V639S15PRF8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 70V639S15PRF8 requirements.

6.How does Aetrix verify that 70V639S15PRF8 is sourced from the original manufacturer or authorized distributors?

All 70V639S15PRF8 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 70V639S15PRF8 meets industry standards.

7.What is the process for return or replacement of 70V639S15PRF8?

All 70V639S15PRF8 units undergo pre-shipment inspection (PSI). If there is an issue with 70V639S15PRF8, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 70V639S15PRF8 part is unused and in its original packaging.

Return procedure for 70V639S15PRF8:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…