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Renesas 71321LA55PFI
- Part No.:
- 71321LA55PFI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA55PFI.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:2,237
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Product details
Overview
IDT71321LA55PFI 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 55 ns max read cycle time, industrial temperature range (–40°C to +85°C), 1 mW standby power, 2 V data retention, and TTL-compatible 5 V ±10% operation. Used in dual-CPU arbitration, shared memory buffers, and real-time control subsystems.
For engineers reviewing the IDT71321LA55PFI datasheet, IDT71321LA55PFI pinout, IDT71321LA55PFI application, or IDT71321LA55PFI equivalent, key selection criteria include dual-port asynchronous access timing, MASTER-mode BUSY output behavior, interrupt mailbox addressing (7FEh/7FFh), battery-backed data retention at 2 V, and compatibility with IDT71421 SLAVE devices in width-expanded configurations.
Technical Context
The IDT71321LA55PFI implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses - enabling concurrent read/write operations without internal synchronization overhead. Its on-chip arbitration logic resolves port contention via BUSY flag generation based solely on chip enable (CEL/CER) and address match detection, not R/W state.
As a MASTER device, it drives open-drain BUSYL/BUSYR outputs requiring 270 Ω pull-up resistors, while supporting interrupt signaling through dedicated INTL/INTR flags tied to fixed mailbox addresses (7FEh and 7FFh). The LA suffix confirms low-power design with 2 V data retention capability and sub-1 mW full-standby current (ISB3 = 0.2 mA typ).
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 |
| Max Read Cycle Time (tRC) | 55 ns - defines minimum interval between successive reads on same port; supports 18.2 MHz burst throughput |
| Standby Current (ISB3) | 0.2 mA typical at VCC = 5 V - enables ultra-low-power retention mode when both CEs are inactive and inputs held CMOS-level |
| Data Retention Voltage | 2.0 V minimum - guarantees nonvolatile data hold during brown-out or backup battery operation |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade reliability in harsh environments without derating |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible single 5 V ±10% rail simplifies power design and eliminates level-shifting |
| Interrupt Mailbox Addresses | 7FEh (INTL set), 7FFh (INTR set) - fixed SRAM locations used for hardware inter-processor signaling |
Pinout & Package
Package: 52-pin STQFP (PPG52), 10 mm × 10 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 (0–2047 decimal) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access; fully independent of left port |
| 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; isolated from left port I/O to prevent bus contention |
| CEL / CER | Chip enable (left/right) | Active-low enables respective port; controls power-down entry/exit (ISB1–ISB4 modes) |
| OEL / OER | Output enable (left/right) | Active-low enables I/O drivers; allows read-only access without disabling CE |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines direction of data flow on active port |
| INTL / INTR | Interrupt flags (output) | Open-drain outputs asserted low when opposite port writes to 7FEh/7FFh |
| BUSYL / BUSYR | BUSY arbitration flags (output) | Open-drain outputs indicating port contention; require 270 Ω pull-up per IDT spec |
| VCC / GND | Power supply pins | Multiple VCC/GND pairs ensure stable noise margin and low-impedance decoupling |
Key Features
| Feature | Design Value |
|---|---|
| Dual-port asynchronous operation | Enables true concurrent access - no clock required, no arbitration delay beyond tBDD (max 50 ns) |
| On-chip BUSY arbitration logic | Hardware-resolved contention detection using CE + address match only; no external logic needed |
| Interrupt mailbox addressing | Fixed 7FEh/7FFh locations provide deterministic inter-processor signaling without software polling |
| 2 V data retention (LA version) | Preserves memory contents during main power loss using backup battery or capacitor hold-up |
| Master/Slave expandability | One IDT71321LA55PFI MASTER coordinates multiple IDT71421 SLAVES for 16+ bit word width systems |
Applications
| Real-Time Dual-CPU Systems | Industrial PLC Memory Buffers |
|---|---|
Use Scenario: Two independent microcontrollers share status, commands, and sensor data via common memory without software locks or semaphores. IC Role / Device Role / Timing Role: IDT71321LA55PFI acts as MASTER dual-port SRAM, providing hardware-enforced atomic access via BUSY flags and interrupt-driven mailbox signaling. Use Value: Eliminates race conditions and CPU idle-wait cycles; 55 ns access enables sub-100 ns inter-processor handshaking latency. |
Use Scenario: Programmable Logic Controller uses shared memory to exchange I/O scan results between control and communication processors. IC Role / Device Role / Timing Role: IDT71321LA55PFI serves as fault-tolerant buffer with 2 V data retention, preserving critical state during AC power interruption. Use Value: Maintains last valid I/O image for safe restart; industrial temp rating ensures operation in uncooled control cabinets. |
| Avionics Data Concentrators | Medical Imaging Frame Buffers |
Use Scenario: Flight data acquisition system routes sensor inputs to multiple processing units with strict determinism and no shared-bus bottlenecks. IC Role / Device Role / Timing Role: IDT71321LA55PFI functions as MASTER in width-expanded array with IDT71421 SLAVES, delivering 16-bit parallel access. Use Value: Enables synchronized sampling across redundant channels; BUSY arbitration prevents corrupted frame writes during simultaneous updates. |
Use Scenario: MRI or CT scanner stores raw pixel data in real time while reconstruction engine reads prior frames concurrently. IC Role / Device Role / Timing Role: IDT71321LA55PFI provides dual-port buffer where acquisition port writes and reconstruction port reads operate independently. Use Value: Sustains >100 MB/s sustained bandwidth (55 ns × 8 bits × 2 ports); low standby power reduces thermal load in sealed enclosures. |
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 CY7C1371DV33-133AXC | 3.3 V core, 133 MHz QDR interface, no built-in BUSY/interrupt logic | Requires external arbitration logic and level shifters; suited for high-bandwidth cache-like use, not interprocessor messaging | Select when migrating to 3.3 V systems and adding custom arbitration; not drop-in compatible |
| IDT71421LA55PFI | SLAVE-only variant; BUSY pins are inputs, no on-chip arbitration logic, identical timing and retention | Must be paired with IDT71321LA55PFI MASTER; used only in width-expanded arrays, not standalone | Choose only as companion device in 16+ bit memory systems; cannot replace MASTER functionality |
Compared with CY7C1371DV33-133AXC and IDT71421LA55PFI, the IDT71321LA55PFI uniquely integrates MASTER arbitration, interrupt mailboxes, and 2 V retention in a single 5 V device - making it irreplaceable for legacy industrial dual-CPU designs requiring hardware-synchronized shared memory.
Availability
IDT71321LA55PFI is available at Aetrix Electronics and suitable for real-time dual-CPU systems, industrial PLC memory buffers, and avionics data concentrators requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for IDT71321LA55PFI 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 IDT71321LA55PFI belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in industrial, aerospace, and medical real-time systems requiring hardware arbitration and battery-backed data integrity.
FAQ
What is the function of the BUSY pins on the IDT71321LA55PFI?
The BUSYL and BUSYR pins on the IDT71321LA55PFI are open-drain outputs that signal port contention when both ports attempt simultaneous access to the same memory location. As a MASTER device, IDT71321LA55PFI asserts these flags to inhibit writes on the contending port - eliminating need for external arbitration logic. Each requires a 270 Ω pull-up resistor per IDT specification DSC-2691.
Does the IDT71321LA55PFI support true simultaneous read/write operations?
Yes - the IDT71321LA55PFI supports fully asynchronous, independent read and write operations on left and right ports. A read on one port and a write on the other can occur concurrently unless they target the same address, in which case BUSY arbitration activates. No clock or synchronization signal is required; timing is governed solely by tRC, tWC, and tBDD parameters.
How does the interrupt functionality work in the IDT71321LA55PFI?
The IDT71321LA55PFI uses fixed SRAM addresses 7FEh (for INTL) and 7FFh (for INTR) as hardware mailboxes. Writing to 7FFh from the left port asserts INTR low; reading 7FFh from the right port clears it. Similarly, 7FEh controls INTL. These are physical memory locations - user data written there serves dual purpose as message payload and interrupt trigger.
Can the IDT71321LA55PFI operate from a 3.3 V supply?
No - the IDT71321LA55PFI is strictly a 5 V ±10% device (4.5 V to 5.5 V). Its input thresholds (VIH = 2.2 V min, VIL = 0.8 V max) and output drive strength are specified only for 5 V operation. Attempting 3.3 V supply will result in undefined logic states, failed data retention at 2 V, and violation of absolute maximum ratings.
What package options are available for the IDT71321LA55PFI?
The IDT71321LA55PFI is offered exclusively in the 52-pin STQFP (PPG52) package: 10 mm × 10 mm body, 1.4 mm height, lead-free and RoHS-compliant. Other variants like PLCC or 64-pin TQFP exist for different speed grades or SA/LA versions, but IDT71321LA55PFI is qualified and shipped only in PPG52 per ordering code PFI suffix.
71321LA55PFI 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:
- 55ns
- Access Time:
- 55 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)
71321LA55PFI FAQ
1.How can I place an order for 71321LA55PFI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA55PFI 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 71321LA55PFI reliable?
The price and inventory of 71321LA55PFI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA55PFI is usually 5 days.
3.What payment methods are accepted for 71321LA55PFI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA55PFI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA55PFI?
71321LA55PFI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA55PFI 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 71321LA55PFI?
For technical support, including 71321LA55PFI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA55PFI requirements.
6.How does Aetrix verify that 71321LA55PFI is sourced from the original manufacturer or authorized distributors?
All 71321LA55PFI 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 71321LA55PFI meets industry standards.
7.What is the process for return or replacement of 71321LA55PFI?
All 71321LA55PFI units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA55PFI, 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 71321LA55PFI part is unused and in its original packaging.
Return procedure for 71321LA55PFI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA55PFI Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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