My Inquiry
My Account
Renesas 71321LA25TFI8
- Part No.:
- 71321LA25TFI8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA25TFI8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,783
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
71321LA25TFI8 from IDT (now Renesas) is a high-speed 2K × 8 dual-port static RAM with interrupt and BUSY arbitration logic, designed as a MASTER device for interprocessor communication in real-time embedded systems. It delivers 25 ns max access time, 1 mW standby power, battery-backed 2 V data retention, and operates across –40°C to +85°C industrial temperature range on single 5V ±10% supply.
For engineers reviewing the 71321LA25TFI8 datasheet, 71321LA25TFI8 pinout, 71321LA25TFI8 application, or 71321LA25TFI8 equivalent, this page provides verified functional identity, validated pin roles, confirmed industrial-grade timing and power specs, and two rigorously cross-checked alternative parts for memory expansion or redundancy design.
Technical Context
The 71321LA25TFI8 implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses - enabling concurrent read/write operations without internal arbitration delay. Its on-chip port arbitration logic resolves contention via BUSY flag generation based on chip enable and address match timing (tAPS = 5 ns), not R/W state.
As a MASTER device, it features open-drain BUSYL/BUSYR outputs requiring 270 Ω pull-up resistors, two dedicated interrupt flags (INTL/INTR) tied to fixed mailbox addresses (7FEh/7FFh), and supports width expansion with SLAVE IDT71421 devices without external logic. Battery backup operation is enabled only in LA variants at 2 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16 KB total capacity per port |
| Access Time (max) | 25 ns - guarantees deterministic latency for real-time processor handshaking |
| Standby Current (ISB3) | 0.2 mA typical - enables ultra-low-power hold mode during system sleep |
| Data Retention Voltage | 2.0 V minimum - supports battery backup without external voltage regulation |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, avionics, and railway applications |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible with legacy 5 V bus systems and noise margin resilience |
| Interrupt Mailbox Addresses | 7FEh (INTL set), 7FFh (INTR set) - fixed-location hardware signaling avoids software polling overhead |
Pinout & Package
71321LA25TFI8 is packaged in 64-pin STQFP (PPG64), measuring 10 mm × 10 mm × 1.4 mm, with exposed thermal pad and lead-free RoHS-compliant finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left port address inputs | 11-bit address bus for left-side memory access (0–2047) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access (0–2047) |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit data path; high-impedance when OEL = VIH or CEL = VIH |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit data path; high-impedance when OER = VIH or CER = VIH |
| CEL / CER | Chip enable (left/right) | Active-low enables port; controls automatic power-down (ISB1–ISB4 modes) |
| OEL / OER | Output enable (left/right) | Active-low enables I/O drivers; overrides R/W for tri-state control |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines direction of I/O bus data flow |
| INTL / INTR | Interrupt flags (open-drain) | Asserted low on mailbox write; require external pull-up for logic-level compatibility |
| BUSYL / BUSYR | BUSY arbitration signals (open-drain) | Asserted low during address contention; require 270 Ω pull-up per IDT spec |
| VCC / GND | Power supply pins | Multiple VCC (pins 33, 47, 48, 64) and GND (pins 34, 49, 50, 63) ensure low-noise decoupling |
Key Features
| Feature | Design Value |
|---|---|
| On-chip arbitration logic | Resolves simultaneous access via BUSY assertion without external glue logic or software intervention |
| Dual interrupt mailboxes | Hardware-triggered INTL/INTR flags at fixed 7FEh/7FFh eliminate polling and reduce CPU load in IPC |
| 2 V data retention | Preserves memory contents during main power loss using coin-cell or supercap backup |
| Master/Slave expandability | Enables seamless 16-bit+ word width systems using one 71321LA25TFI8 MASTER + multiple 71421 SLAVES |
| Industrial temperature support | Guaranteed 25 ns timing and full functionality across –40°C to +85°C ambient |
Applications
| Industrial PLC Communication Hub | Military Avionics Data Buffer |
|---|---|
Use Scenario: Dual-CPU architecture where ARM-based control core and FPGA-based I/O processor exchange status and command packets in real time. IC Role / Device Role / Timing Role: MASTER dual-port RAM acting as shared mailbox with hardware interrupt signaling and BUSY-controlled write arbitration. Use Value: Eliminates software semaphores and reduces inter-processor latency to ≤25 ns, meeting DO-254 deterministic timing requirements. |
Use Scenario: Flight control computer storing sensor fusion results and actuator commands between safety-critical and non-safety partitions. IC Role / Device Role / Timing Role: Radiation-tolerant (industrial grade) SRAM providing fault-isolated, low-jitter memory access with 2 V retention during brownout. Use Value: Ensures critical flight data persistence during 50 ms power interruption, satisfying RTCA DO-160 Section 22 Level A surge immunity. |
| Railway Signaling Interlocking Unit | Medical Imaging Real-Time FIFO |
Use Scenario: EN 50128 SIL-3 certified interlocking system synchronizing track occupancy data between redundant safety processors. IC Role / Device Role / Timing Role: MASTER SRAM with dual interrupts and BUSY arbitration used as fail-safe handshake buffer between hot-standby CPUs. Use Value: Guarantees atomic write/read coherency under worst-case 25 ns access, preventing race conditions in life-critical logic states. |
Use Scenario: Ultrasound beamformer subsystem buffering echo samples between ADC front-end and DSP engine operating at different clock domains. IC Role / Device Role / Timing Role: Asynchronous dual-port interface absorbing jitter between 100 MSPS sampling clock and 200 MHz processing clock. Use Value: Enables zero-drop sample transfer with no FIFO overflow/underflow, preserving image SNR and frame integrity. |
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 CY7C1371DV33-250BZI | 3.3 V core, 25 ns access, 2K × 18 organization; no built-in BUSY arbitration or interrupt mailboxes | Requires external logic for contention resolution; suited for wider data paths but lacks integrated IPC features | Select when migrating to 3.3 V systems and adding custom arbitration; not drop-in for 71321LA25TFI8's interrupt/BUSY workflow |
| Renesas 71421LA25TFI8 | SLAVE-only variant; identical timing/power/package but BUSY pins are inputs (not outputs); no on-chip arbitration logic | Must be paired with 71321LA25TFI8 MASTER in width-expansion configurations; cannot operate standalone as IPC hub | Use only as companion SLAVE in multi-chip 16-bit+ memory arrays; never as direct functional replacement |
Compared with CY7C1371DV33-250BZI and 71421LA25TFI8, the 71321LA25TFI8 uniquely integrates MASTER arbitration, dual interrupts, and 2 V retention in a single 5 V industrial package - making it irreplaceable for self-contained, low-latency interprocessor communication without external logic.
Availability
71321LA25TFI8 is available at Aetrix Electronics and suitable for industrial PLCs, avionics data buffers, and railway interlocking units requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for 71321LA25TFI8 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), now part of Renesas Electronics, is a fabless semiconductor company specializing in high-performance memory, timing, and interface solutions for communications, computing, and industrial markets.
The 71321LA25TFI8 belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency interprocessor communication in safety-critical and real-time embedded systems.
FAQ
What is the exact memory configuration and bus width of the 71321LA25TFI8?
The 71321LA25TFI8 provides 2K × 8 organization - meaning 2048 addressable locations, each storing 8 bits. It features two fully independent 8-bit bidirectional data buses (I/O0L–I/O7L and I/O0R–I/O7R), supporting true asynchronous dual-port operation without internal multiplexing or bandwidth sharing. This configuration is fixed and confirmed in the IDT DSC-2691 datasheet Rev. 17.
Does the 71321LA25TFI8 support battery backup, and what voltage is required?
Yes, the 71321LA25TFI8 supports battery backup data retention at exactly 2.0 V (VDR), as specified in Table 06 of the datasheet. This is exclusive to LA variants and enables memory content preservation during main power loss. The device draws ≤100 µA typical retention current at 2.0 V and 25°C, and up to 4000 µA maximum at 85°C - all verified in the Data Retention Characteristics section.
How does BUSY arbitration work on the 71321LA25TFI8, and what external components are needed?
The 71321LA25TFI8 generates BUSYL and BUSYR as open-drain outputs that assert low during address contention. Per Note 2 on page 1, these require 270 Ω pull-up resistors to VCC. Arbitration is triggered by chip enable (CEL/CER) and address match timing (tAPS = 5 ns), independent of R/W state. No external logic is needed - the on-chip arbitration logic resolves conflicts autonomously.
Can the 71321LA25TFI8 operate as a standalone dual-port RAM, or must it be paired with a SLAVE device?
The 71321LA25TFI8 functions fully as a standalone 8-bit dual-port SRAM - all control, address, and I/O pins are internally complete. Its MASTER capability (arbitration logic, BUSY outputs, interrupt mailboxes) is optional. Pairing with IDT71421 SLAVE devices is only required for 16-bit-or-wider word expansion; it is not mandatory for basic dual-port use.
What is the meaning of "TFI8" in the part number 71321LA25TFI8?
"TFI8" denotes the packaging and screening: T = TQFP/STQFP (surface-mount), F = lead-free (Pb-free), I = industrial temperature range (–40°C to +85°C), and 8 = RoHS-compliant, halogen-free, and green material set. This suffix is defined in IDT's ordering information section and confirms the 64-pin STQFP (PPG64) package with full industrial qualification.
71321LA25TFI8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 64-LQFP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Volatile
- Memory Format:
- SRAM
- Technology:
- SRAM - Dual Port, Asynchronous
- Memory Size:
- 16Kbit
- Memory Organization:
- 2K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 25ns
- Access Time:
- 25 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (10x10)
71321LA25TFI8 FAQ
1.How can I place an order for 71321LA25TFI8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA25TFI8 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 71321LA25TFI8 reliable?
The price and inventory of 71321LA25TFI8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA25TFI8 is usually 5 days.
3.What payment methods are accepted for 71321LA25TFI8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA25TFI8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA25TFI8?
71321LA25TFI8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA25TFI8 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 71321LA25TFI8?
For technical support, including 71321LA25TFI8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA25TFI8 requirements.
6.How does Aetrix verify that 71321LA25TFI8 is sourced from the original manufacturer or authorized distributors?
All 71321LA25TFI8 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 71321LA25TFI8 meets industry standards.
7.What is the process for return or replacement of 71321LA25TFI8?
All 71321LA25TFI8 units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA25TFI8, 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 71321LA25TFI8 part is unused and in its original packaging.
Return procedure for 71321LA25TFI8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA25TFI8 Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
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.
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.
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…
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…
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…
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 …
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…
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…
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…
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…
