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Renesas 71V321LA55PF
- Part No.:
- 71V321LA55PF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71V321LA55PF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,337
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Product details
Overview
71V321LA55PF from Renesas Electronics is a high-speed 3.3V 2K × 8 dual-port static RAM with on-chip interrupt logic and BUSY arbitration, designed for interprocessor communication in embedded control systems. It delivers 55 ns read/write cycle time, supports independent asynchronous access from left/right ports, and features battery-backed data retention down to 2.0 V. Used in real-time industrial controllers requiring concurrent memory access.
For engineers reviewing the 71V321LA55PF datasheet, 71V321LA55PF pinout, 71V321LA55PF application, or 71V321LA55PF equivalent, this page provides verified technical context, validated pin functions, confirmed timing behavior under contention, and real-world use cases in dual-CPU architectures where deterministic port arbitration is critical.
Technical Context
The 71V321LA55PF implements fully asynchronous dual-port operation with separate address, control, and I/O buses per port-no shared clock required. Its on-chip arbitration logic uses address and chip-enable matching (not R/W state) to assert BUSYL/BUSYR outputs, enabling hardware stall signaling during simultaneous access to identical memory locations.
Interrupt functionality is implemented via dedicated mailbox addresses: writing to 0x7FE (HEX) on the right port sets INTL; writing to 0x7FF sets INTR. Both flags are cleared by reading the respective address with OE active. All interrupt timing-including tINS ≤ 45 ns and tINR ≤ 45 ns-is specified for the 55 ns speed grade.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 bits (2048 words × 8-bit data bus per port) |
| Access Time (tAA) | 55 ns max - defines worst-case delay from stable address to valid output data |
| Read/Write Cycle (tRC / tWC) | 55 ns max - minimum time between successive read or write operations |
| Supply Voltage | 3.0 V to 3.6 V - TTL-compatible single 3.3 V rail; no level shifters needed |
| Data Retention Voltage | 2.0 V min - enables battery backup operation without external regulators |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments with full parameter guarantees |
| Standby Current (ISB3) | 0.2 mA typ. - ultra-low power mode when both ports disabled with CMOS-level inputs |
Pinout & Package
71V321LA55PF is packaged in a 64-pin TQFP (Thin Quad Flatpack), measuring 10 mm × 10 mm × 1.4 mm, with lead-free (Green) finish and RoHS compliance. The package supports fine-pitch PCB layout and thermal dissipation suitable for dense industrial modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left port address inputs | 11-bit address bus for left-side memory access (0x000–0x7FF) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access (0x000–0x7FF) |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit data path; tristated when OEL = VIH or CEL = VIH |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit data path; tristated when OER = VIH or CER = VIH |
| CEL / CER | Chip enable (left/right) | Active-low enables port access and powers internal circuitry; VIH places port in standby |
| OEL / OER | Output enable (left/right) | Active-low controls data bus direction: VIL enables output drivers, VIH forces high-Z |
| R/WL / R/WR | Read/write control (left/right) | Active-low selects write mode; VIH enables read operation |
| BUSYL / BUSYR | Arbitration status outputs | Totem-pole outputs indicating port contention; asserted low when opposite port accesses same address |
| INTL / INTR | Interrupt flag outputs | Open-drain compatible (per datasheet note), asserted low upon mailbox write (0x7FE/0x7FF) |
| VCC / GND | Power supply pins | Multiple VCC (pins 16, 32, 48, 64) and GND (pins 1, 17, 33, 49) ensure low-impedance distribution |
Key Features
| Feature | Design Value |
|---|---|
| Dual-port arbitration logic | Hardware-based BUSY assertion eliminates software polling overhead during address contention |
| Interprocessor interrupt mailbox | Dedicated 0x7FE/0x7FF addresses enable zero-latency CPU-to-CPU signaling without shared registers |
| Asynchronous port independence | No clock synchronization required-ports operate at different frequencies or phases without conflict |
| Battery-backed data retention | Maintains stored data at 2.0 V supply, enabling seamless switchover to backup power in PLCs |
| Low-power standby modes | ISB3 = 0.2 mA typ. reduces system power during idle cycles without sacrificing wake-up latency |
Applications
| Industrial PLC Dual-CPU Architecture | Real-Time Motion Controller |
|---|---|
|
Use Scenario: Two independent microcontrollers coordinate motion sequencing and safety monitoring using shared memory. IC Role / Device Role / Timing Role: 71V321LA55PF serves as the synchronized memory bridge, with BUSY signals halting writes during concurrent access to prevent race conditions. Use Value: Deterministic 55 ns arbitration ensures sub-microsecond response to contention, meeting SIL-3 timing constraints. |
Use Scenario: A master DSP handles trajectory calculation while a slave MCU manages I/O and encoder feedback. IC Role / Device Role / Timing Role: 71V321LA55PF provides non-blocking memory access; INTL/INTR flags signal completion of motion segments. Use Value: 45 ns interrupt set/reset timing enables <100 ns inter-core handshaking, reducing jitter in closed-loop control. |
| Avionics Data Concentrator | Medical Imaging Subsystem |
|
Use Scenario: ARINC 429 interface processor and flight management unit share sensor fusion results via common memory. IC Role / Device Role / Timing Role: 71V321LA55PF operates across –40°C to +85°C with guaranteed 55 ns timing, supporting DO-254 compliance. Use Value: 2.0 V data retention allows uninterrupted memory state during brownout events in airborne power systems. |
Use Scenario: FPGA-based image acquisition engine and ARM Cortex-A9 processor exchange DICOM metadata and raw pixel buffers. IC Role / Device Role / Timing Role: 71V321LA55PF decouples high-bandwidth pixel streaming from metadata processing via independent ports. Use Value: 0.2 mA ISB3 current minimizes thermal load in sealed MRI cabinet 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 |
|---|---|---|---|
| CY7C024AV-55AXC | 55 ns access, 2K × 16 organization, 3.3 V supply, no integrated BUSY logic | Requires external arbitration circuitry; better suited for wider data paths | Select when 16-bit data bus and external control logic are acceptable |
| AS7C3256B-55JCIN | 55 ns access, 32K × 8 organization, 3.3 V supply, no interrupt or BUSY outputs | Larger memory depth but lacks hardware interprocessor signaling features | Select when mailbox interrupts and contention detection are not required |
Compared with CY7C024AV-55AXC and AS7C3256B-55JCIN, the 71V321LA55PF uniquely integrates BUSY arbitration and interrupt mailbox logic-reducing BOM count and PCB area in tightly coupled dual-CPU designs where deterministic inter-core coordination is mandatory.
Availability
71V321LA55PF is available at Aetrix Electronics and suitable for industrial PLCs, real-time motion controllers, avionics data concentrators, and medical imaging subsystems requiring stable component supply with long-term lifecycle support.
Supply support for 71V321LA55PF 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
Renesas Electronics Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and infrastructure markets.
The 71V321LA55PF belongs to Renesas' legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in safety-critical embedded systems requiring hardware-enforced memory coherency.
FAQ
What is the maximum operating temperature range for the 71V321LA55PF?
The 71V321LA55PF is rated for industrial operation from –40°C to +85°C, with all AC and DC parameters fully guaranteed across this range. This includes 55 ns access timing, BUSY arbitration behavior, and interrupt flag response, making it suitable for harsh environments like factory automation and outdoor telecom equipment.
Does the 71V321LA55PF require external pull-up resistors on BUSY or INT pins?
No. The 71V321LA55PF features totem-pole BUSYL and BUSYR outputs, and INTL/INTR outputs are compatible with open-drain configurations but do not require external pull-ups for standard operation. The datasheet explicitly states BUSY outputs are totem-pole and need no external components.
How does the 71V321LA55PF handle simultaneous access to the same memory location?
When both ports attempt access to identical addresses, the 71V321LA55PF asserts BUSYL or BUSYR low within 30 ns (tBDD max), blocking the later-arriving write. The winning port proceeds; the stalled port must wait until BUSY deasserts. This hardware arbitration prevents data corruption without software intervention.
What is the function of address locations 0x7FE and 0x7FF in the 71V321LA55PF?
In the 71V321LA55PF, 0x7FE serves as the left-port interrupt mailbox: a write to this address by the right port sets INTL. Similarly, 0x7FF is the right-port mailbox: a write by the left port sets INTR. Reading either address clears the corresponding flag-enabling lightweight inter-CPU messaging.
Can the 71V321LA55PF retain data during power loss?
Yes. The 71V321LA55PF supports data retention down to 2.0 V (VDR min), consuming only 100 µA typical (ICCDR) at 2 V. This allows integration with coin-cell or supercapacitor backup circuits to preserve memory state during main power interruption in industrial controllers.
71V321LA55PF 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:
- 3V ~ 3.6V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (14x14)
71V321LA55PF FAQ
1.How can I place an order for 71V321LA55PF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71V321LA55PF 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 71V321LA55PF reliable?
The price and inventory of 71V321LA55PF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71V321LA55PF is usually 5 days.
3.What payment methods are accepted for 71V321LA55PF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71V321LA55PF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71V321LA55PF?
71V321LA55PF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71V321LA55PF 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 71V321LA55PF?
For technical support, including 71V321LA55PF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71V321LA55PF requirements.
6.How does Aetrix verify that 71V321LA55PF is sourced from the original manufacturer or authorized distributors?
All 71V321LA55PF 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 71V321LA55PF meets industry standards.
7.What is the process for return or replacement of 71V321LA55PF?
All 71V321LA55PF units undergo pre-shipment inspection (PSI). If there is an issue with 71V321LA55PF, 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 71V321LA55PF part is unused and in its original packaging.
Return procedure for 71V321LA55PF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71V321LA55PF Tags
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M24C02-WMN6TP
STMicroelectronics
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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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