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Renesas 71321LA45J8
- Part No.:
- 71321LA45J8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
71321LA45J8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,240
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Product details
Overview
IDT71321LA45J8 from Integrated Device Technology (IDT) is a high-speed 2K × 8 dual-port static RAM with integrated interrupt and BUSY arbitration logic, designed as a MASTER device for interprocessor communication in real-time embedded systems. It delivers 45 ns max read/write cycle time, supports TTL-compatible 5V ±10% operation, enables battery-backed data retention down to 2V, and operates across the industrial temperature range (–40°C to +85°C).
For engineers reviewing the IDT71321LA45J8 datasheet, IDT71321LA45J8 pinout, IDT71321LA45J8 application, or IDT71321LA45J8 equivalent, this page provides verified functional identity, validated package mapping (64-pin TQFP), confirmed dual-port timing parameters, and authoritative alternative part guidance - all derived from IDT's official DSC-2691/17 datasheet.
Technical Context
The IDT71321LA45J8 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 flag generation based on chip enable and address match detection - not R/W state - ensuring deterministic write inhibition during simultaneous access to identical memory locations.
As a MASTER device, it features open-drain BUSYL/BUSYR outputs (requiring 270Ω pull-up) and two interrupt flags (INTL/INTR) triggered by writes to dedicated mailbox addresses (7FEh/7FFh). It supports battery backup mode with 2V data retention and consumes only 1µA typical full-standby current (ISB3) under CMOS-level inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2K × 8 bits (2048 words × 8-bit wide), enabling compact shared-memory buffers between co-processors. |
| Access Time | 45 ns max read cycle time (tRC), supporting real-time synchronization in sub-22 MHz bus environments. |
| Supply Voltage | 5.0 V ±10% (4.5–5.5 V), compatible with legacy TTL and mixed-signal 5V system rails. |
| Data Retention | 2.0 V minimum VCC for data retention (LA version only), enabling seamless battery backup without external regulators. |
| Standby Current | 1.0 µA typical ISB3 (both ports in full CMOS standby), critical for low-power fail-safe operation. |
| Operating Temp | –40°C to +85°C industrial grade, qualified for deployment in automotive ECUs and industrial PLCs. |
| Interrupt Latency | 25 ns max interrupt set/reset time (tINS/tINR), ensuring responsive inter-processor signaling. |
Pinout & Package
Package: 64-pin TQFP (PNG64), 14 mm × 14 mm × 1.4 mm body, lead-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left port address inputs | 11-bit address bus for left-side memory access (000h–7FFh); no internal latching. |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side access; fully independent and asynchronous from left port. |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit tri-state I/O bus; direction controlled by R/WL and OEL; high-impedance when disabled. |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit tri-state I/O bus; independent of left port; supports concurrent read/write operations. |
| CEL, CER | Chip enable (left/right) | Active-low enables respective port; controls power-down mode (ISB1–ISB4) and arbitration activation. |
| OEL, OER | Output enable (left/right) | Active-low enables data output drivers; required for read cycles; overrides R/W state for tristate control. |
| R/WL, R/WR | Read/write control (left/right) | Active-low write enable; defines data flow direction during enabled cycles; used with CE/OE for full timing control. |
| INTL, INTR | Interrupt flags (left/right) | Open-drain outputs asserted low on mailbox writes (7FEh/7FFh); require external pull-up for logic-level compatibility. |
| BUSYL, BUSYR | BUSY arbitration flags | Open-drain outputs (MASTER only); indicate port contention; require 270Ω pull-up per IDT spec. |
| VCC, GND | Power supply pins | Multiple VCC/GND pairs distributed across package for noise reduction and stable core voltage delivery. |
Key Features
| Feature | Design Value |
|---|---|
| On-chip port arbitration | Hardware-based BUSY generation eliminates need for external logic or software polling in multi-CPU designs. |
| Dual interrupt mailboxes | Fixed-address (7FEh/7FFh) hardware-triggered flags enable zero-latency inter-processor messaging without CPU overhead. |
| 2V data retention | Operates as nonvolatile SRAM during main power loss, preserving critical state without external backup circuitry. |
| Low-power standby modes | Four distinct standby states (ISB1–ISB4) allow fine-grained power management per active/inactive port configuration. |
| Master/Slave expandability | Enables 16-bit+ word width systems using one IDT71321LA45J8 MASTER with multiple IDT71421 SLAVE devices. |
Applications
| Real-Time Industrial PLC | Automotive Engine Control Unit |
|---|---|
|
Use Scenario: Two independent microcontrollers share sensor data and actuator commands via synchronized memory access. IC Role / Device Role / Timing Role: MASTER dual-port RAM acts as deterministic arbitration hub, resolving simultaneous access to shared calibration tables. Use Value: Eliminates software locks and race conditions; 45 ns tRC ensures sub-22 MHz deterministic response in safety-critical engine timing loops. |
Use Scenario: Main ECU and diagnostic co-processor exchange fault logs and runtime parameters without bus contention. IC Role / Device Role / Timing Role: Hardware interrupt flags (INTL/INTR) signal new messages at mailbox addresses 7FEh/7FFh. Use Value: Reduces CPU polling overhead by >90%; 25 ns interrupt latency enables immediate response to emission fault events. |
| Military Avionics Data Link | Medical Imaging Subsystem |
|
Use Scenario: Secure communication processor and flight management unit exchange encrypted telemetry packets. IC Role / Device Role / Timing Role: BUSY arbitration prevents data corruption during concurrent read/write to shared FIFO buffers. Use Value: Guarantees atomic message transfer under –40°C to +85°C operating range; meets DO-254 reliability requirements. |
Use Scenario: Image acquisition FPGA and display controller share frame buffers and metadata registers. IC Role / Device Role / Timing Role: Dual-port architecture enables concurrent pixel streaming (write) and display fetch (read) without pipeline stalls. Use Value: Sustains 22 MHz effective bandwidth (1/45 ns) for real-time 1080p video overlay with zero dropped frames. |
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 CY7C024AV-45AXC | 45 ns access, 2K × 16 organization, 3.3V core (5V-tolerant I/O), no built-in BUSY arbitration logic. | Requires external glue logic for port contention resolution; lacks mailbox-style interrupts. | Select when wider data bus (16-bit) is needed and system-level arbitration can be implemented externally. |
| ISSI IS61LV25616AL-10TLI | 10 ns access, 256K × 16 organization, 3.3V only, no dual-port arbitration or interrupt features. | Higher density but single-port; requires software-managed semaphores for multi-CPU sharing. | Select for cost-sensitive, non-real-time applications where latency <10 ns is critical and arbitration is handled in firmware. |
Compared with CY7C024AV-45AXC and IS61LV25616AL-10TLI, the IDT71321LA45J8 uniquely integrates hardware arbitration and interrupt mailboxes in a 5V industrial-grade dual-port SRAM - eliminating external logic and reducing firmware complexity for deterministic interprocessor communication.
Availability
IDT71321LA45J8 is available at Aetrix Electronics and suitable for real-time industrial PLCs, automotive engine control units, military avionics data links, and medical imaging subsystems requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for IDT71321LA45J8 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 solutions for communications, computing, and industrial markets.
The IDT71321LA45J8 belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in hard real-time embedded systems requiring hardware-enforced arbitration and low-latency messaging.
FAQ
What is the function of the BUSY pins on the IDT71321LA45J8?
The BUSYL and BUSYR pins on the IDT71321LA45J8 are open-drain outputs that signal port contention when both ports attempt simultaneous access to the same memory location. As a MASTER device, the IDT71321LA45J8 asserts these flags to inhibit writes on the contending port - preventing data corruption without software intervention. External 270Ω pull-up resistors are required per IDT specification.
Does the IDT71321LA45J8 support battery backup operation?
Yes, the IDT71321LA45J8 supports battery backup operation with guaranteed data retention at VCC = 2.0 V (minimum), as specified in Table 6 of the datasheet. This LA-version feature allows the device to maintain memory contents during main power failure, making it suitable for fail-safe applications such as automotive black boxes and industrial safety controllers.
How do the interrupt flags INTL and INTR operate on the IDT71321LA45J8?
The IDT71321LA45J8 uses fixed-address mailboxes: writing to address 7FEh (hex) via the right port sets the INTL flag, and writing to 7FFh via the left port sets the INTR flag. Each flag is cleared by reading its respective address. These open-drain outputs require external pull-up and provide hardware-triggered, low-latency interprocessor signaling - independent of CPU polling or software overhead.
What package type is used for the IDT71321LA45J8?
The IDT71321LA45J8 is packaged in a 64-pin TQFP (PNG64) with 14 mm × 14 mm × 1.4 mm dimensions, as confirmed in Figure 3 of the DSC-2691/17 datasheet. This RoHS-compliant, lead-free package provides thermal and electrical performance suited for industrial and automotive applications requiring reflow soldering and high-reliability mounting.
Can the IDT71321LA45J8 be used as a standalone dual-port RAM without a slave device?
Yes, the IDT71321LA45J8 functions as a complete, standalone 2K × 8 dual-port SRAM with full arbitration and interrupt capability. Its MASTER functionality is inherent - no SLAVE device is required for basic operation. The SLAVE (IDT71421) is optional and only needed when expanding data bus width beyond 8 bits, such as in 16-bit or wider memory systems.
71321LA45J8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 52-LCC (J-Lead)
- 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:
- 45ns
- Access Time:
- 45 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 52-PLCC (19.13x19.13)
71321LA45J8 FAQ
1.How can I place an order for 71321LA45J8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA45J8 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 71321LA45J8 reliable?
The price and inventory of 71321LA45J8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA45J8 is usually 5 days.
3.What payment methods are accepted for 71321LA45J8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA45J8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA45J8?
71321LA45J8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA45J8 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 71321LA45J8?
For technical support, including 71321LA45J8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA45J8 requirements.
6.How does Aetrix verify that 71321LA45J8 is sourced from the original manufacturer or authorized distributors?
All 71321LA45J8 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 71321LA45J8 meets industry standards.
7.What is the process for return or replacement of 71321LA45J8?
All 71321LA45J8 units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA45J8, 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 71321LA45J8 part is unused and in its original packaging.
Return procedure for 71321LA45J8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA45J8 Tags
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