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Renesas 71321LA20PFG
- Part No.:
- 71321LA20PFG
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA20PFG.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:601
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Product details
Overview
IDT71321LA20PFG 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 in real-time embedded systems. It features 20 ns max read cycle time, 5 V ±10% single-supply operation, industrial temperature range (–40°C to +85°C), and battery-backed data retention down to 2 V - enabling use in fault-tolerant controller memory buffers.
For engineers reviewing the IDT71321LA20PFG datasheet, IDT71321LA20PFG pinout, IDT71321LA20PFG application, or IDT71321LA20PFG equivalent, key selection criteria include dual-port arbitration timing (tBAA/tBDD), interrupt mailbox address mapping (7FEH/7FFH), low-power standby current (1 µA typical), and 64-pin TQFP package compatibility with legacy IDT71321/71421 designs.
Technical Context
The IDT71321LA20PFG implements fully asynchronous dual-port access with independent left/right control, address, 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 addresses.
As a MASTER device, it provides open-drain BUSYL/BUSYR outputs (requiring 270 Ω pull-up) and two interrupt flags (INTL/INTR) tied to dedicated mailbox addresses (7FEH and 7FFH). It supports battery backup mode with 2 V data retention and consumes only 1 µA in full CMOS standby (ISB3), distinguishing it from SA variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 bits (2048 words × 8-bit wide), dual-port SRAM with independent left/right access paths |
| Access Time (tRC) | 20 ns max - enables direct interface with 50 MHz bus controllers without wait states |
| Supply Voltage | 5.0 V ±10% - TTL-compatible single supply; no separate VCC rails required |
| Standby Current (ISB3) | 0.2 µA typical at 25°C - enables ultra-low-power battery backup operation |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, avionics, and railway signaling applications |
| Data Retention Voltage | 2.0 V minimum - preserves memory contents during main power loss with external backup battery |
| Interrupt Mailbox Addresses | 7FEH (sets INTL), 7FFH (sets INTR) - software-accessible message registers for 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; latched on CEL or R/WL transition |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side access; independent timing from left port |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit tri-state I/O; direction controlled by R/WL; high-impedance when OEL = VIH |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit tri-state I/O; direction controlled by R/WR; high-impedance when OER = VIH |
| CEL, CER | Chip enable inputs | Active-low enables for respective ports; controls power-down entry (ISB1–ISB4 modes) |
| OEL, OER | Output enable inputs | Active-low enables output drivers; high-impedance when disabled |
| R/WL, R/WR | Read/write control | Active-low write enable; determines I/O direction and internal write pulse timing (tWP) |
| BUSYL, BUSYR | Arbitration status outputs | Open-drain BUSY flags - require 270 Ω pull-up; assert LOW to inhibit writes during contention |
| INTL, INTR | Interrupt flag outputs | Active-high flags set/cleared by mailbox writes (7FEH/7FFH); edge-triggered for CPU polling |
| VCC, GND | Power supply pins | Four VCC and four GND pins distributed for low-noise operation and EMI reduction |
Key Features
| Feature | Design Value |
|---|---|
| On-chip port arbitration logic | Resolves simultaneous access to same address without external logic; uses tAPS (5 ns setup) to guarantee priority |
| Dual interrupt mailbox architecture | Hardware-integrated 8-bit mailboxes at 7FEH (left INT) and 7FFH (right INT) enable lock-free inter-processor messaging |
| 2 V data retention mode | Preserves full 2K × 8 memory content during main power failure using external 2 V battery - unique to LA variant |
| Low-power standby (ISB3) | 0.2 µA typical current draw when both ports disabled with CMOS-level inputs - critical for battery-backed systems |
| Master/Slave expandability | Enables 16-bit+ word width systems using one IDT71321LA20PFG (MASTER) + multiple IDT71421LA20PFG (SLAVE) devices |
Applications
| Industrial PLC Memory Buffer | Avionics Flight Control Interface |
|---|---|
Use Scenario: Dual-CPU redundancy system where primary and backup processors share status and command data in real time. IC Role / Device Role / Timing Role: MASTER dual-port SRAM acts as shared memory hub with hardware arbitration preventing write collisions during failover transitions. Use Value: Eliminates need for external arbitration logic and reduces firmware complexity; 20 ns access ensures sub-50 ns inter-processor latency. |
Use Scenario: Real-time sensor fusion module requiring deterministic exchange of IMU, GPS, and actuator feedback between safety-critical partitions. IC Role / Device Role / Timing Role: Dual-port RAM provides non-blocking read/write paths for partition-isolated CPUs; BUSY logic enforces atomic updates to shared control registers. Use Value: Guarantees data coherency without software locks; 2 V retention maintains last-known-safe state during brownout events. |
| Railway Signaling Controller | Medical Imaging Data Pipeline |
Use Scenario: EN 5012x-certified signaling interlocking unit exchanging track occupancy and route commands across redundant processing channels. IC Role / Device Role / Timing Role: IDT71321LA20PFG serves as certified shared memory with interrupt-driven mailbox protocol for event notification. Use Value: Hardware interrupts (INTL/INTR) reduce CPU polling overhead; industrial temp rating ensures reliability in uncontrolled cabinet environments. |
Use Scenario: High-throughput ultrasound beamformer where FPGA-acquired raw data must be concurrently accessed by DSP for real-time filtering and ARM for display buffering. IC Role / Device Role / Timing Role: Dual-port SRAM decouples acquisition and processing pipelines; independent left/right timing prevents pipeline stalls. Use Value: 20 ns access enables >40 MB/s sustained throughput per port; TQFP package supports dense PCB layouts in compact imaging modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IDT71321SA20PFG | No 2 V data retention; higher ISB3 (15 µA vs. 0.2 µA); same speed/package | Suitable for commercial-temp, non-battery-backed systems only | Select when cost sensitivity outweighs retention requirement and industrial temp is not needed |
| Cypress CY7C024AV-20AXC | 3.3 V core supply; different pinout (52-pin TQFP); no built-in BUSY arbitration | Requires external logic for contention resolution; incompatible with IDT71421 slave expansion | Choose only if migrating to 3.3 V design and redesigning arbitration circuitry |
Compared with IDT71321SA20PFG, the IDT71321LA20PFG delivers 75× lower full-standby current and guaranteed 2 V retention - essential for fail-safe systems. Versus CY7C024AV-20AXC, it retains pin-compatible MASTER/SLAVE scalability and eliminates external arbitration components.
Availability
IDT71321LA20PFG is available at Aetrix Electronics and suitable for industrial PLC memory buffers, avionics flight control interfaces, and railway signaling controllers requiring stable component supply across extended product lifecycles.
Supply support for IDT71321LA20PFG 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, and RF power solutions for communications and industrial markets.
The IDT71321LA series was designed specifically for deterministic interprocessor communication in safety-critical embedded systems - emphasizing hardware arbitration, interrupt mailboxing, and ultra-low-power retention.
FAQ
What is the function of BUSYL and BUSYR on the IDT71321LA20PFG?
BUSYL and BUSYR are open-drain arbitration status outputs on the IDT71321LA20PFG. When asserted LOW, they indicate port contention - i.e., simultaneous access to the same memory address from both ports - and internally inhibit write operations on the affected port. Each requires a 270 Ω pull-up resistor to VCC. These signals enable hardware-based, deterministic resolution without software intervention, a core feature of the IDT71321LA20PFG MASTER architecture.
How does the IDT71321LA20PFG support battery backup operation?
As an LA-series device, the IDT71321LA20PFG guarantees data retention at VCC = 2.0 V with typical current draw of 100 µA (max 1500 µA) - enabling use with coin-cell or supercapacitor backup. This functionality is absent in SA variants. The IDT71321LA20PFG enters retention mode automatically when main supply drops below threshold while CE pins remain high, preserving all 2K × 8 memory contents without external control logic.
Can the IDT71321LA20PFG be used as a SLAVE device in a Master/Slave configuration?
No - the IDT71321LA20PFG is exclusively a MASTER device. Its BUSYL/BUSYR pins are outputs, and it contains on-chip arbitration logic. For SLAVE operation, IDT specifies the IDT71421LA20PFG, which has BUSY pins as inputs and lacks arbitration circuitry. Attempting to use IDT71321LA20PFG as a SLAVE will cause functional conflict due to mismatched BUSY signal direction and logic behavior.
What are the interrupt mailbox addresses for the IDT71321LA20PFG?
The IDT71321LA20PFG uses fixed interrupt mailbox addresses: 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. Reading either address clears the corresponding flag. These locations are user-accessible SRAM cells - the 8-bit data written becomes the message payload, enabling flexible inter-processor communication without dedicated register space.
Is the IDT71321LA20PFG pin-compatible with other speed grades in the same package?
Yes - all IDT71321LA variants in the 64-pin TQFP (PNG64) package, including IDT71321LA25PFG and IDT71321LA35PFG, share identical pinouts and electrical interface. Speed grade differences affect only timing parameters (e.g., tRC = 20 ns vs. 25 ns); no PCB layout change is required when upgrading or downgrading within the LA family, provided system timing margins accommodate the slower variant.
71321LA20PFG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 64-LQFP
- Packaging:
- Tray
- Product Status:
- Active
- 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:
- 20ns
- Access Time:
- 20 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)
71321LA20PFG FAQ
1.How can I place an order for 71321LA20PFG through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA20PFG 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 71321LA20PFG reliable?
The price and inventory of 71321LA20PFG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA20PFG is usually 5 days.
3.What payment methods are accepted for 71321LA20PFG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA20PFG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA20PFG?
71321LA20PFG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA20PFG 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 71321LA20PFG?
For technical support, including 71321LA20PFG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA20PFG requirements.
6.How does Aetrix verify that 71321LA20PFG is sourced from the original manufacturer or authorized distributors?
All 71321LA20PFG 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 71321LA20PFG meets industry standards.
7.What is the process for return or replacement of 71321LA20PFG?
All 71321LA20PFG units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA20PFG, 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 71321LA20PFG part is unused and in its original packaging.
Return procedure for 71321LA20PFG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA20PFG Tags
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