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Renesas 71321LA55PF8
- Part No.:
- 71321LA55PF8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA55PF8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,704
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Product details
Overview
71321LA55PF8 from Integrated Device Technology (IDT) is a high-speed 2K × 8 dual-port static RAM with interrupt and BUSY arbitration logic, designed as a MASTER device for interprocessor communication. It delivers 55 ns max read/write cycle time, 2V battery-backed data retention, industrial temperature operation (–40°C to +85°C), and TTL-compatible 5V ±10% supply - used in real-time embedded systems requiring concurrent access to shared memory buffers.
For engineers reviewing the 71321LA55PF8 datasheet, 71321LA55PF8 pinout, 71321LA55PF8 application, or 71321LA55PF8 equivalent, key selection criteria include its MASTER arbitration capability, dual-interrupt flag support (INTL/INTR), low 1 µA full-standby current, and compatibility with SLAVE IDT71421 devices in 16-bit+ bus expansion architectures.
Technical Context
The 71321LA55PF8 implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves port contention via BUSY output (open-drain, requires 270 Ω pull-up) triggered by address match detection - not dependent on R/W direction.
Interrupt functionality uses dedicated mailbox addresses (7FEH for INTL, 7FFH for INTR) with set/reset timing defined by tINS ≤ 45 ns and tINR ≤ 45 ns. Battery backup mode operates at VCC = 2.0 V with guaranteed data retention and ICCDR ≤ 4000 µA (industrial grade).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 bits (2048 words × 8-bit wide), dual-access random access |
| Access Time (tAA) | 55 ns max - defines minimum address hold before valid data appears |
| Read Cycle Time (tRC) | 55 ns max - sets minimum interval between successive reads on same port |
| Full Standby Current (ISB3) | 10 µA max at VCC = 2.0 V - enables ultra-low-power battery retention mode |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded control and communications |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible with standard 5V logic systems and noise margin |
| Interrupt Timing (tINS/tINR) | ≤ 45 ns - ensures fast interprocessor signaling latency in real-time co-processing |
Pinout & Package
71321LA55PF8 is packaged in a 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 parallel data path; high-impedance when OEL = VIH or CEL = VIH |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit parallel data path; high-impedance when OER = VIH or CER = VIH |
| CEL / CER | Chip enable (left/right) | Active-low enables respective port; controls power-down entry (ISB1–ISB4) |
| OEL / OER | Output enable (left/right) | Active-low enables outputs; does not affect internal memory access or power state |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines data flow direction on I/O bus |
| INTL / INTR | Interrupt flags (output) | Open-drain outputs asserting on mailbox writes (7FEH/7FFH) |
| BUSYL / BUSYR | BUSY arbitration signals | BUSYL/BUSYR are outputs on 71321LA55PF8 (MASTER); require 270 Ω pull-up |
| VCC, GND | Power and ground | Multiple VCC/GND pins distributed for low-noise, stable 5V operation |
Key Features
| Feature | Design Value |
|---|---|
| On-chip port arbitration logic | Resolves simultaneous access conflicts without external logic; asserts BUSY on contended port within 20–30 ns |
| Dual interrupt mailbox addressing | Hardware-automated interprocessor signaling using dedicated SRAM locations 7FEH (INTL) and 7FFH (INTR) |
| 2V battery backup data retention | Maintains stored contents during main power loss; validated at VCC = 2.0 V, TA = +25°C |
| Low-power LA variant | Reduces full-standby current to 10 µA (vs. 45 µA in SA version), critical for battery-powered systems |
| Master/Slave expandability | Enables seamless 16-bit+ word-width memory systems using one 71321LA55PF8 MASTER + multiple IDT71421 SLAVES |
Applications
| Real-Time Dual-Core Processor Interface | Industrial PLC Shared Memory Buffer |
|---|---|
Use Scenario: Two independent microcontrollers exchange sensor data and control commands via shared memory without software polling or OS-level synchronization. IC Role / Device Role / Timing Role: 71321LA55PF8 acts as MASTER dual-port RAM with hardware BUSY arbitration and interrupt flags to coordinate atomic read/write operations across cores. Use Value: Eliminates race conditions and reduces inter-core latency to ≤45 ns interrupt response, enabling deterministic sub-millisecond task handoff. | Use Scenario: A programmable logic controller uses separate I/O processor and motion control processor sharing status registers, command queues, and fault logs. IC Role / Device Role / Timing Role: 71321LA55PF8 provides non-blocking concurrent access to 2KB of shared configuration and runtime data with battery-backed retention during power cycling. Use Value: Ensures zero-data-loss persistence across brownouts and supports hot-swappable firmware updates without memory reinitialization. |
| Avionics Data Concentrator | Medical Imaging Frame Buffer |
Use Scenario: Multiple sensor acquisition modules (ARINC 429, discrete I/O) feed time-stamped telemetry into a central flight management unit. IC Role / Device Role / Timing Role: 71321LA55PF8 serves as MASTER buffer with interrupt-driven mailbox protocol to signal new packet arrival from any input channel. Use Value: Guarantees bounded interrupt latency (<45 ns) and eliminates CPU polling overhead, improving system determinism for DO-178C certification. | Use Scenario: Ultrasound or MRI systems acquire raw pixel data at high throughput while display subsystem renders previous frames. IC Role / Device Role / Timing Role: 71321LA55PF8 operates as dual-port frame buffer - acquisition engine writes to one port while rendering engine reads from the other. Use Value: Enables continuous 55 ns-cycle pipelined data flow without FIFO bottlenecks or frame tearing, supporting real-time 60+ fps imaging. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IDT71421LA55PF8 | SLAVE-only device; BUSY pins are inputs (not outputs); no on-chip arbitration logic | Requires pairing with a MASTER (e.g., 71321LA55PF8) for arbitration; cannot operate standalone as memory controller | Select only when expanding bus width beyond 8 bits using MASTER/SLAVE topology |
| Cypress CY7C1371DV33-55BGXI | 3.3V core supply (not 5V); different pinout; no built-in interrupt mailboxes or BUSY arbitration | Needs external logic for interrupt generation and port contention resolution; incompatible with legacy 5V TTL systems | Choose only for new 3.3V designs where external arbitration is acceptable and voltage scaling is required |
Compared with IDT71421LA55PF8 and CY7C1371DV33-55BGXI, the 71321LA55PF8 uniquely integrates MASTER arbitration, dual interrupts, and 5V/2V dual-supply operation - making it irreplaceable in legacy industrial and avionics systems requiring self-contained, drop-in dual-port memory coordination.
Availability
71321LA55PF8 is available at Aetrix Electronics and suitable for real-time embedded systems, industrial PLCs, avionics data concentrators, and medical imaging equipment requiring stable component supply and long-term lifecycle support.
Supply support for 71321LA55PF8 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 high-performance computing solutions.
The IDT71321/71421 family was engineered specifically for deterministic interprocessor communication in safety-critical and real-time embedded systems - emphasizing hardware arbitration, low-latency interrupts, and robust industrial temperature operation.
FAQ
What is the maximum operating speed of the 71321LA55PF8?
The 71321LA55PF8 has a maximum read/write cycle time (tRC) of 55 ns, corresponding to a theoretical peak bandwidth of ~18.2 MHz per port. This speed is guaranteed across the full industrial temperature range (–40°C to +85°C) under VCC = 4.5–5.5 V, and applies to both left and right ports independently.
Does the 71321LA55PF8 support battery backup operation?
Yes, the 71321LA55PF8 supports true battery backup operation at VCC = 2.0 V, retaining all 2K × 8 bits of data with ICCDR ≤ 4000 µA (industrial grade). This is a defining feature of the "LA" suffix variant and is not available in the "SA" (standard active) version.
How does BUSY arbitration work on the 71321LA55PF8?
On the 71321LA55PF8, BUSY arbitration is implemented as open-drain outputs (BUSYL/BUSYR) that assert low when both ports attempt simultaneous access to the same memory address. The assertion occurs within ≤30 ns (tBDD) and blocks writes on the delayed port - no external logic is needed, and the decision is based solely on address and chip-enable timing alignment.
Can the 71321LA55PF8 be used without interrupt functionality?
Yes, the 71321LA55PF8 operates fully as a dual-port SRAM without using interrupts. Addresses 7FEH and 7FFH function as standard memory locations unless explicitly used for mailbox signaling. Disabling interrupts requires no hardware changes - simply avoid writing to those addresses or ignore INTL/INTR outputs.
What package type is used for the 71321LA55PF8?
The 71321LA55PF8 uses a 64-pin STQFP package (PPG64), measuring 10 mm × 10 mm × 1.4 mm with an exposed thermal pad. This RoHS-compliant, lead-free package supports fine-pitch PCB assembly and provides superior thermal performance over PLCC alternatives.
71321LA55PF8 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:
- 55ns
- Access Time:
- 55 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (14x14)
71321LA55PF8 FAQ
1.How can I place an order for 71321LA55PF8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA55PF8 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 71321LA55PF8 reliable?
The price and inventory of 71321LA55PF8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA55PF8 is usually 5 days.
3.What payment methods are accepted for 71321LA55PF8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA55PF8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA55PF8?
71321LA55PF8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA55PF8 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 71321LA55PF8?
For technical support, including 71321LA55PF8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA55PF8 requirements.
6.How does Aetrix verify that 71321LA55PF8 is sourced from the original manufacturer or authorized distributors?
All 71321LA55PF8 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 71321LA55PF8 meets industry standards.
7.What is the process for return or replacement of 71321LA55PF8?
All 71321LA55PF8 units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA55PF8, 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 71321LA55PF8 part is unused and in its original packaging.
Return procedure for 71321LA55PF8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA55PF8 Tags
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