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Renesas 71321LA25PFI
- Part No.:
- 71321LA25PFI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA25PFI.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,114
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Product details
Overview
71321LA25PFI from Integrated Device Technology 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 operates at 25 ns max access time, supports industrial temperature (–40°C to +85°C), features 2V battery backup data retention, and uses a single 5V ±10% supply. It enables error-free 16-bit+ memory expansion when paired with IDT71421 SLAVE devices in embedded control systems.
For engineers reviewing the 71321LA25PFI datasheet, 71321LA25PFI pinout, 71321LA25PFI application, or 71321LA25PFI equivalent, key selection considerations include its MASTER arbitration capability, dual-interrupt flag architecture (INTL/INTR), BUSY output behavior, 2V data retention support, and compatibility with 52-pin STQFP packaging for space-constrained industrial designs.
Technical Context
The 71321LA25PFI implements fully asynchronous dual-port operation with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves port contention using chip-enable and address-match timing - asserting BUSYL/BUSYR outputs when both ports access identical addresses, with tAPS = 5 ns priority setup time.
Interrupt functionality is implemented via dedicated mailbox addresses: INTL asserts on right-port write to 0x7FE, INTR on left-port write to 0x7FF; both flags are cleared by read-access to their respective addresses. The device requires external 270Ω pull-up resistors on open-drain BUSY and INT pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2K × 8 bits (2048 words × 8-bit wide), enabling compact shared-memory buffers between two processors |
| Access Time | 25 ns (max) - guarantees deterministic latency for real-time inter-processor handshaking |
| Data Retention | 2 V minimum - supports battery-backed operation during main power loss without external circuitry |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard TTL/5V logic domains without level translation |
| Standby Current | 1 µA (typ) - ultra-low ISB3 full-standby mode extends battery life in always-on monitoring systems |
| Operating Temp | –40°C to +85°C - qualified for industrial control, motor drives, and transportation electronics |
| Package | 52-pin STQFP (PPG52) - 10 mm × 10 mm footprint with exposed pad for thermal management |
Pinout & Package
71321LA25PFI is housed in a 52-pin STQFP (PPG52) package with exposed thermal pad. Pin functions are defined per the official IDT pinout diagram for PPG52 configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left-port address inputs | 11-bit address bus for left-side processor access to full 2K memory space |
| I/O0L–I/O7L | Left-port bidirectional data | 8-bit data path; high-impedance when OEL = VIH or CEL = VIH |
| R/WL, CEL, OEL | Left-port control signals | Asynchronous read/write enable; CE-driven power-down reduces active current to 1 µA |
| INTL, BUSYL | Left-port interrupt & BUSY | Open-drain outputs requiring 270Ω pull-up; BUSYL blocks writes during contention |
| A0R–A10R | Right-port address inputs | Independent 11-bit address bus - enables true concurrent access from second processor |
| I/O0R–I/O7R | Right-port bidirectional data | Separate 8-bit data path; electrically isolated from left port I/O |
| R/WR, CER, OER | Right-port control signals | Full control independence - no shared clocks or synchronization required |
| INTR, BUSYR | Right-port interrupt & BUSY | Open-drain outputs; INTR asserted on left-port write to 0x7FF; BUSYR input on SLAVE devices |
| VCC, GND | Power & ground | Multiple VCC/GND pins distributed across package for low-noise 5V operation |
Key Features
| Feature | Design Value |
|---|---|
| On-chip arbitration logic | Resolves simultaneous same-address access without external logic - eliminates race conditions in dual-CPU systems |
| Dual interrupt mailbox | Hardware-accelerated interprocessor signaling via dedicated 0x7FE/0x7FF addresses - avoids polling overhead |
| Battery backup retention | Maintains valid data at 2V supply - enables seamless failover in power-critical industrial controllers |
| Master/Slave expandability | Enables 16-bit+ word width systems using one 71321LA25PFI MASTER + multiple 71421 SLAVES - no glue logic needed |
| Ultra-low standby power | 1 µA typical ISB3 current - suitable for battery-powered remote I/O modules with long sleep intervals |
Applications
| Industrial PLC Communication Buffer | Automotive Engine Control Dual-Core Interface |
|---|---|
Use Scenario: Two independent microcontrollers in a programmable logic controller exchange status and command data via shared memory. IC Role / Device Role / Timing Role: 71321LA25PFI acts as MASTER dual-port SRAM, providing synchronized, contention-free access with hardware BUSY arbitration. Use Value: Eliminates software semaphores and reduces inter-core latency to ≤25 ns, improving scan cycle consistency in safety-critical motion control. | Use Scenario: Main ECU and auxiliary diagnostics processor share sensor calibration tables and fault logs in real time. IC Role / Device Role / Timing Role: 71321LA25PFI serves as interrupt-enabled mailbox memory, with INTL/INTR flags triggering context-switch events. Use Value: Enables deterministic response to diagnostic requests within 25 ns interrupt set time, meeting ISO 26262 ASIL-B timing constraints. |
| Medical Imaging Data Pipeline | Avionics Flight Management System |
Use Scenario: Image acquisition FPGA streams raw pixel data while ARM-based UI processor reads processed frames for display. IC Role / Device Role / Timing Role: 71321LA25PFI provides asynchronous, non-blocking dual-port buffer with 2V data retention during power transitions. Use Value: Guarantees zero-frame-loss buffering during hot-swap of imaging modules, supported by 1 µA standby current and robust BUSY flow control. | Use Scenario: Redundant flight computers maintain synchronized navigation state through shared memory with fail-safe arbitration. IC Role / Device Role / Timing Role: 71321LA25PFI operates as MASTER in a triple-modular-redundant (TMR) configuration with external voting logic. Use Value: Hardware BUSY arbitration prevents conflicting writes during transient faults, ensuring atomic state updates per DO-254 design assurance requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C136-25JC | 5V, 2K × 8, 25 ns, but lacks integrated BUSY arbitration and interrupt logic; requires external logic for contention resolution | No native mailbox or automatic port arbitration - increases BOM count and PCB area in multi-processor systems | Select when legacy Cypress footprint compatibility is required and arbitration can be handled externally |
| IDT71421LA25PFI | Same family, LA grade, 25 ns, but SLAVE-only: BUSY pins are inputs only; no on-chip arbitration logic | Cannot operate standalone as MASTER; must be paired with 71321LA25PFI in width-expanded configurations | Select only as companion SLAVE in 16-bit+ memory systems where 71321LA25PFI handles arbitration |
Compared with CY7C136-25JC, 71321LA25PFI integrates arbitration and interrupts, reducing system-level complexity; compared with IDT71421LA25PFI, it provides autonomous MASTER functionality essential for standalone dual-processor interfaces.
Availability
71321LA25PFI is available at Aetrix Electronics and suitable for industrial PLCs, automotive engine control units, medical imaging subsystems, and avionics data concentrators requiring stable component supply across extended product lifecycles.
Supply support for 71321LA25PFI 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 power management ICs for communications and computing infrastructure.
The IDT71321/71421 product line was engineered specifically for deterministic, low-latency interprocessor communication in real-time embedded systems - emphasizing hardware arbitration, interrupt signaling, and battery-backed reliability.
FAQ
What is the function of the BUSY pins on the 71321LA25PFI?
The BUSYL and BUSYR pins on the 71321LA25PFI are open-drain outputs that signal port contention. When both ports attempt to access the same memory address, the on-chip arbitration logic asserts the corresponding BUSY pin LOW to inhibit writes on the delayed port. This prevents data corruption without software intervention. External 270Ω pull-up resistors are required per the 71321LA25PFI datasheet.
Does the 71321LA25PFI support true simultaneous read/write operations?
Yes - the 71321LA25PFI supports fully asynchronous, independent read and write operations on left and right ports. Each port has dedicated address, data, and control lines, allowing concurrent access to different memory locations. When accessing the same location, hardware arbitration via BUSY ensures deterministic resolution with ≤25 ns timing, preserving data integrity in the 71321LA25PFI.
How does interrupt handling work in the 71321LA25PFI?
The 71321LA25PFI implements hardware interrupts via dedicated mailbox addresses: writing to 0x7FE sets INTL (left-port flag), and writing to 0x7FF sets INTR (right-port flag). Flags are cleared by reading those same addresses. This eliminates polling and enables event-driven interprocessor communication. The 71321LA25PFI interrupt timing is guaranteed at ≤25 ns set/reset, supporting hard real-time response.
Can the 71321LA25PFI operate without external pull-up resistors on BUSY and INT pins?
No - the BUSYL, BUSYR, INTL, and INTR pins on the 71321LA25PFI are open-drain outputs and require external pull-up resistors. The datasheet specifies 270Ω for proper logic-level definition and timing compliance. Omitting these resistors will result in undefined HIGH states, failed arbitration, and unreliable interrupt signaling in the 71321LA25PFI.
What is the significance of the 'LA' suffix in 71321LA25PFI?
'LA' denotes the low-power, battery-backup variant of the IDT71321. The 71321LA25PFI guarantees data retention down to 2V supply voltage and achieves 1 µA typical full-standby current (ISB3), unlike the 'SA' (standard active) version. This makes the 71321LA25PFI suitable for applications requiring persistent memory during brownouts or battery-only operation.
71321LA25PFI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 64-LQFP
- Packaging:
- Tray
- 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 (14x14)
71321LA25PFI FAQ
1.How can I place an order for 71321LA25PFI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA25PFI 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 71321LA25PFI reliable?
The price and inventory of 71321LA25PFI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA25PFI is usually 5 days.
3.What payment methods are accepted for 71321LA25PFI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA25PFI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA25PFI?
71321LA25PFI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA25PFI 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 71321LA25PFI?
For technical support, including 71321LA25PFI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA25PFI requirements.
6.How does Aetrix verify that 71321LA25PFI is sourced from the original manufacturer or authorized distributors?
All 71321LA25PFI 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 71321LA25PFI meets industry standards.
7.What is the process for return or replacement of 71321LA25PFI?
All 71321LA25PFI units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA25PFI, 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 71321LA25PFI part is unused and in its original packaging.
Return procedure for 71321LA25PFI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA25PFI Tags
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