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Renesas 71321SA25JI
- Part No.:
- 71321SA25JI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
71321SA25JI.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:2,163
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Product details
Overview
IDT71321SA25JI from Integrated Device Technology is a high-speed 2K × 8 dual-port static RAM with on-chip port arbitration, two interrupt flags (INTL/INTR), and BUSY signaling for interprocessor communication. It operates at 25 ns max access time, supports industrial temperature range (–40°C to +85°C), consumes 110 mA dynamic current (typ.), and uses a single 5V ±10% supply. It serves as the MASTER device in MASTER/SLAVE memory expansion systems for 16-bit-or-wider data buses.
For engineers reviewing the 71321SA25JI datasheet, 71321SA25JI pinout, 71321SA25JI application, or 71321SA25JI equivalent, key selection criteria include its 25 ns read cycle time, dual asynchronous port operation, integrated arbitration logic, interrupt mailbox addressing (7FEh/7FFh), and compatibility with IDT71421SLAVE devices in width-expanded systems.
Technical Context
The 71321SA25JI implements fully independent left/right ports with separate address, control, and I/O lines, enabling true asynchronous concurrent read/write access to any memory location. Its on-chip arbitration logic resolves contention via BUSY flag generation based on chip enable and address match timing - not R/W state - ensuring deterministic priority resolution without external logic.
As a MASTER-only device, it features open-drain BUSYL/BUSYR outputs requiring 270 Ω pull-ups, supports interrupt-driven interprocessor messaging via dedicated mailbox addresses (7FEh for INTL, 7FFh for INTR), and enables battery-backed data retention only in LA variants - not applicable to this SA-grade part.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16,384 total bits |
| Max Access Time | 25 ns (industrial grade, guaranteed over –40°C to +85°C) |
| Supply Voltage | 5.0 V ±10% (4.5 V to 5.5 V), single rail, TTL-compatible |
| Dynamic Current (ICC) | 110 mA typ. (both ports active, f = fMAX) |
| Standby Current (ISB1) | 30 mA typ. (both ports disabled, TTL-level inputs) |
| Interrupt Addresses | INTL asserted on right-port write to 7FEh; INTR on left-port write to 7FFh |
| BUSY Arbitration | Hardware-based, triggered by CE/address match; no software overhead |
Pinout & Package
71321SA25JI is packaged in a 52-pin STQFP (PPG52), measuring 10 mm × 10 mm × 1.4 mm, with exposed thermal pad (not electrically connected). All VCC and GND pins must be properly decoupled per layout guidelines.
| 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 respective port; controls power-down mode when high |
| OEL / OER | Output enable (left/right) | Active-low enables data output drivers; does not affect write path |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines direction of I/O bus |
| INTL / INTR | Interrupt flags (open-drain) | INTL: left-port interrupt output; INTR: right-port interrupt output |
| BUSYL / BUSYR | BUSY arbitration signals | Open-drain outputs (MASTER only); require 270 Ω pull-up to VCC |
| VCC / GND | Power supply terminals | Multiple VCC/GND pins ensure low-noise operation and thermal dissipation |
Key Features
| Feature | Design Value |
|---|---|
| On-chip port arbitration logic | Resolves simultaneous access conflicts deterministically using CE/address timing - eliminates need for external arbitration circuitry |
| Dual interrupt mailbox architecture | Enables lock-free interprocessor messaging via dedicated SRAM locations (7FEh/7FFh), reducing software polling overhead |
| Asynchronous dual-port operation | Allows independent, non-synchronized reads/writes on left and right ports - critical for real-time co-processor systems |
| Master-only BUSY signaling | Provides hardware write-inhibit coordination in width-expanded arrays with IDT71421 SLAVE devices, preventing partial-word corruption |
| Industrial temperature support | Guaranteed 25 ns performance across –40°C to +85°C ambient, suitable for embedded control and avionics |
Applications
| Real-Time Dual-Processor Systems | Industrial PLC Memory Buffers |
|---|---|
Use Scenario: Two independent microcontrollers share status and command data without shared bus contention or software locks. IC Role / Device Role / Timing Role: 71321SA25JI acts as MASTER dual-port RAM, providing atomic mailbox access and hardware arbitration between CPU A and CPU B. Use Value: Eliminates race conditions and reduces inter-CPU latency to ≤25 ns, enabling deterministic response in motion control loops. |
Use Scenario: Programmable Logic Controller stores I/O scan results and configuration parameters accessible by both control engine and HMI processor. IC Role / Device Role / Timing Role: 71321SA25JI serves as shared memory buffer with interrupt-driven notification of new sensor data or updated setpoints. Use Value: Enables zero-copy data exchange and guarantees data consistency across temperature extremes (–40°C to +85°C). |
| Avionics Data Acquisition Nodes | Medical Imaging Frame Buffers |
Use Scenario: Flight computer writes raw sensor telemetry while health monitor reads same memory region for diagnostics. IC Role / Device Role / Timing Role: 71321SA25JI provides isolated, concurrent access paths with BUSY arbitration to prevent write collisions during fault detection. Use Value: Ensures uninterrupted data capture at 25 ns access speed, meeting DO-254 timing constraints for safety-critical subsystems. |
Use Scenario: MRI system buffers digitized image frames between acquisition FPGA and display processor. IC Role / Device Role / Timing Role: 71321SA25JI functions as low-latency frame store with interrupt signaling to trigger DMA transfers upon full-frame availability. Use Value: Sustains burst throughput without CPU intervention, leveraging dual-port concurrency to avoid pipeline stalls in real-time imaging pipelines. |
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 supply, 250 MHz QDR interface, no built-in BUSY arbitration | Requires external logic for contention resolution; suited for high-bandwidth streaming, not interprocessor messaging | Select if migrating to 3.3 V systems and adding custom arbitration; not drop-in compatible |
| IDT71421SA25JI | SLAVE-only variant; BUSY pins are inputs, no arbitration logic, no INTL/INTR flags | Used only in width-expanded arrays paired with 71321SA25JI; cannot operate standalone as MASTER | Required companion for 16-bit+ memory expansion; never substitutes for 71321SA25JI's MASTER functionality |
Compared with CY7C1371DV33-250BZI, 71321SA25JI delivers integrated hardware arbitration and interrupt messaging at 5 V, simplifying dual-CPU designs; compared with IDT71421SA25JI, it provides the essential MASTER logic required for autonomous arbitration and mailbox management - making it irreplaceable in standalone dual-processor topologies.
Availability
71321SA25JI is available at Aetrix Electronics and suitable for real-time dual-processor systems, industrial PLC memory buffers, and avionics data acquisition nodes requiring stable component supply, long-term lifecycle support, and guaranteed industrial-temperature performance.
Supply support for 71321SA25JI 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, specializes in high-performance timing, memory interface, and RF power solutions for communications, computing, and industrial markets.
The IDT71321 family was designed specifically for deterministic interprocessor communication in resource-constrained embedded systems, emphasizing hardware arbitration, low-latency dual-port access, and robust industrial operation - not general-purpose memory expansion.
FAQ
What is the operating temperature range for the 71321SA25JI?
The 71321SA25JI is rated for industrial temperature operation from –40°C to +85°C. This specification is guaranteed across all electrical parameters including 25 ns access time, standby current, and interrupt timing. The "I" suffix in the part number explicitly denotes industrial grade qualification, validated per IDT's internal stress and burn-in protocols.
Does the 71321SA25JI support battery backup data retention?
No, the 71321SA25JI does not support battery backup data retention. That capability is exclusive to LA-grade variants (e.g., 71321LA25JI), which specify 2.0 V data retention voltage and microamp-level retention current. The "SA" suffix indicates standard active-power operation only, with no retention mode or associated low-voltage circuitry.
Can the 71321SA25JI be used without a companion SLAVE device?
Yes, the 71321SA25JI functions fully as a standalone 8-bit dual-port SRAM. Its MASTER arbitration logic remains internally active but does not impair operation when used alone. BUSYL/BUSYR outputs default to high-impedance unless contention occurs - and since no external BUSY input is present, arbitration applies only to internal port conflicts.
What pull-up resistor value is required for BUSYL and BUSYR on the 71321SA25JI?
IDT specifies a 270 Ω pull-up resistor to VCC for both BUSYL and BUSYR pins on the 71321SA25JI. This value ensures valid logic-high levels under worst-case sink current (16 mA) while maintaining fast rise times consistent with the 25 ns timing budget. Using higher resistance may violate tHZ or cause metastability in arbitration decisions.
How are the interrupt mailboxes addressed in the 71321SA25JI?
The 71321SA25JI uses fixed SRAM addresses for interrupt signaling: writing to address 7FEh (hex) via the right port asserts INTL, and writing to 7FFh via the left port asserts INTR. These locations are ordinary memory cells - the interrupt function is purely behavioral, requiring no special register mapping or configuration bits within the 71321SA25JI.
71321SA25JI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 52-LCC (J-Lead)
- Packaging:
- Tube
- 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:
- 52-PLCC (19.13x19.13)
71321SA25JI FAQ
1.How can I place an order for 71321SA25JI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321SA25JI 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 71321SA25JI reliable?
The price and inventory of 71321SA25JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321SA25JI is usually 5 days.
3.What payment methods are accepted for 71321SA25JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321SA25JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321SA25JI?
71321SA25JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321SA25JI 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 71321SA25JI?
For technical support, including 71321SA25JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321SA25JI requirements.
6.How does Aetrix verify that 71321SA25JI is sourced from the original manufacturer or authorized distributors?
All 71321SA25JI 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 71321SA25JI meets industry standards.
7.What is the process for return or replacement of 71321SA25JI?
All 71321SA25JI units undergo pre-shipment inspection (PSI). If there is an issue with 71321SA25JI, 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 71321SA25JI part is unused and in its original packaging.
Return procedure for 71321SA25JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321SA25JI Tags
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