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Renesas 71V321SA25PF8
- Part No.:
- 71V321SA25PF8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71V321SA25PF8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,099
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Product details
Overview
71V321SA25PF8 from Renesas Electronics is a high-speed 3.3V 2K × 8 dual-port static RAM with interrupt logic and on-chip arbitration, designed for interprocessor communication in real-time embedded systems. It delivers 25 ns max access time, supports fully asynchronous operation from either port, and features two independent TTL-compatible I/O ports with BUSY and INT flags. Used in industrial control backplanes and redundant processor synchronization.
For engineers reviewing the 71V321SA25PF8 datasheet, 71V321SA25PF8 pinout, 71V321SA25PF8 application, or 71V321SA25PF8 equivalent, key selection criteria include dual-port arbitration timing (tBDD ≤ 30 ns), interrupt flag set/reset latency (tINS/tINR ≤ 25 ns), 3.3V-only supply compatibility, and PLCC/TQFP package options - all critical for deterministic memory coherency in safety-critical dual-CPU designs.
Technical Context
The 71V321SA25PF8 implements hardware-based port arbitration using totem-pole BUSY outputs (BUSYL/BUSYR) that assert when both ports access the same address simultaneously, blocking writes on the contending port. Its interrupt logic uses dedicated mailbox addresses (7FEH for INTL, 7FFH for INTR) with edge-triggered flag assertion and software-clear capability.
It operates in three power states: active (ICC ≤ 55 mA typ.), standby with TTL-level inputs (ISB1 ≤ 15 mA), and full standby with CMOS-level inputs (ISB3 ≤ 1.0 mA typ.). Data retention at 2.0 V is supported only in L-version variants; the 'S' suffix denotes standard-power operation without battery backup.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 bits (2048 words × 8-bit data bus per port) |
| Access Time (max) | 25 ns - defines minimum read/write cycle time for deterministic timing in real-time systems |
| Supply Voltage | 3.0 V to 3.6 V - single 3.3V rail operation; no 5V tolerance |
| Operating Temperature | 0°C to +70°C - commercial grade; not rated for industrial −40°C to +85°C range |
| Power Consumption (active) | 55 mA typical - translates to ~182 mW at 3.3V, enabling thermal budgeting in dense PCB layouts |
| Interrupt Latency | tINS ≤ 25 ns - ensures sub-30ns response to inter-processor mailbox writes for tight synchronization |
| Arbitration Priority Setup | tAPS ≥ 5 ns - minimum setup time required before address match to guarantee deterministic BUSY assertion |
Pinout & Package
71V321SA25PF8 is packaged in a 64-pin TQFP (Thin Quad Flatpack), code PNG64, body size 10 mm × 10 mm × 1.4 mm. All VCC and GND pins must be connected per datasheet layout guidelines to ensure signal integrity and thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left port address inputs | 11-bit address bus for left-side memory access; decoded internally to select one of 2048 locations |
| I/O0L–I/O7L | Left port bidirectional data bus | 8-bit parallel interface; direction controlled by R/WL and OEL; high-impedance when deselected |
| CEL, OEL, R/WL | Left port control signals | Chip Enable, Output Enable, Read/Write - define active-low enable hierarchy for left-side access |
| BUSYL, INTL | Left port status outputs | BUSYL = totem-pole busy indicator; INTL = open-drain interrupt flag asserted on right-port write to 7FEH |
| A0R–A10R | Right port address inputs | Independent 11-bit address bus; enables concurrent access to same or different memory locations |
| I/O0R–I/O7R | Right port bidirectional data bus | Electrically isolated from left port; supports simultaneous read/write if addresses differ |
| CER, OER, R/WR | Right port control signals | Functionally identical to left-side controls but operate independently; no shared logic |
| BUSYR, INTR | Right port status outputs | BUSYR blocks right-port writes during contention; INTR asserts on left-port write to 7FFH |
| VCC, GND | Power and ground | Four VCC and four GND pins distributed across package corners - mandatory for low-noise operation |
Key Features
| Feature | Design Value |
|---|---|
| Dual-port arbitration logic | Hardware-enforced conflict resolution via BUSY outputs eliminates need for external semaphores or polling loops |
| Interprocessor interrupt mailbox | Dedicated SRAM addresses 7FEH/7FFH serve as hardware-triggered message flags with <25 ns latency |
| Asynchronous port independence | Full read/write capability on either port at any time - no clock or synchronization required between ports |
| Low-power standby modes | Three-tier power management: ISB1 (15 mA), ISB3 (1.0 mA typ.), and full disable via CE-driven power-down |
| TTL-compatible 3.3V interface | VIH = 2.0 V min, VIL = 0.8 V max - interoperable with legacy 3.3V logic families without level shifters |
Applications
| Industrial PLC Backplane Memory | Redundant CPU Synchronization |
|---|---|
|
Use Scenario: Two independent PLC CPUs share configuration and I/O state data via a common memory space. IC Role / Device Role / Timing Role: Dual-port RAM acts as coherent shared memory buffer with hardware arbitration preventing simultaneous writes to same register. Use Value: Eliminates software locks and reduces inter-CPU latency to ≤25 ns for real-time state updates. |
Use Scenario: Primary and backup microcontrollers maintain identical runtime contexts and switch seamlessly on fault detection. IC Role / Device Role / Timing Role: 71V321SA25PF8 provides atomic mailbox communication (INTL/INTR) for heartbeat and failover signaling. Use Value: Sub-30 ns interrupt assertion enables deterministic switchover within 100 µs total system recovery time. |
| Avionics Data Concentrator Buffer | Medical Imaging Frame Store |
|
Use Scenario: Sensor acquisition unit and flight control processor concurrently access telemetry buffers without bus contention. IC Role / Device Role / Timing Role: Acts as non-blocking dual-access frame buffer with BUSY-driven stall signaling for deterministic pipeline flow. Use Value: Enables continuous 10 MB/s sensor streaming while allowing real-time control reads without dropped samples. |
Use Scenario: MRI subsystem acquires raw image frames while display controller renders prior frames - requiring zero-copy memory sharing. IC Role / Device Role / Timing Role: Provides independent read/write ports for acquisition and rendering engines accessing overlapping memory regions. Use Value: Supports simultaneous 25 ns access to 2K×8 pixel metadata, eliminating frame buffering delays in real-time diagnostics. |
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 CY7C024AV-25AXC | 2K × 16 organization; 25 ns access; 3.3V; includes JTAG boundary scan | Wider data bus suits 16-bit processors; lacks dedicated interrupt mailbox logic | Choose when 16-bit interface or debug visibility outweighs interrupt-driven messaging needs |
| Renesas 71V3556SA25PFGI | 4K × 16 organization; 25 ns; industrial temp (−40°C to +85°C); same pinout family | Higher density and extended temperature rating; requires PCB redesign due to 80-pin TQFP | Choose for upgraded capacity and harsh environment operation - not drop-in compatible |
Compared with CY7C024AV-25AXC and 71V3556SA25PFGI, the 71V321SA25PF8 uniquely balances 8-bit bus simplicity, hardware interrupt mailboxes, and commercial-grade cost-making it optimal for cost-sensitive dual-CPU systems where deterministic 25 ns coherency and mailbox signaling are primary requirements.
Availability
71V321SA25PF8 is available at Aetrix Electronics and suitable for industrial PLC backplanes, redundant CPU synchronization, and avionics data concentrators requiring stable component supply and long-term production continuity.
Supply support for 71V321SA25PF8 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 automotive, industrial, and infrastructure markets.
The 71V321SA25PF8 belongs to Renesas' legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time embedded systems with strict timing and coherency requirements.
FAQ
What is the maximum operating temperature range for the 71V321SA25PF8?
The 71V321SA25PF8 is specified for commercial temperature range only: 0°C to +70°C. It is not rated for industrial −40°C to +85°C operation. This is confirmed by the ordering code suffix 'C' in the part number and the Recommended Operating Conditions table (DSC-3026/14, page 3), which lists TA = 0°C to +70°C for commercial grade. Industrial variants exist (e.g., 71V321L25PFGI) but carry distinct orderable IDs.
Does the 71V321SA25PF8 support battery backup data retention?
No, the 71V321SA25PF8 does not support battery backup data retention. The 'S' suffix denotes Standard-power operation, whereas only 'L' (Low-power) versions - such as 71V321L25PF8 - specify VDR = 2.0 V minimum and tCDR up to 1000 µs for data retention. The 71V321SA25PF8 datasheet contains no data retention characteristics, confirming its exclusion from this feature.
How does the BUSY arbitration logic function in the 71V321SA25PF8?
The 71V321SA25PF8 asserts BUSYL or BUSYR when both ports access the same memory address simultaneously. The arbitration is based solely on chip enable (CE) and address match - not on read/write type. If contention occurs, the port satisfying tAPS ≥ 5 ns wins; the losing port's BUSY output goes low, gating its write signals internally. Both BUSY outputs are totem-pole, requiring no external pull-ups.
What are the valid interrupt mailbox addresses for the 71V321SA25PF8?
The 71V321SA25PF8 uses fixed SRAM addresses for interrupt signaling: writing to address 7FEH (2046 decimal) from the right port asserts INTL; writing to 7FFH (2047 decimal) from the left port asserts INTR. These locations are user-defined memory cells - not reserved registers - and retain standard SRAM functionality when interrupts are unused. Clearing is performed by reading the same address with OE and CE active.
Is the 71V321SA25PF8 pin-compatible with other members of the 71V321 family?
The 71V321SA25PF8 shares the same 64-pin TQFP (PNG64) footprint and pinout with all other 71V321 variants in that package, including 71V321L25PFG and 71V321L35PFGI. Signal mapping, power, and ground pin locations are identical across speed grades and power variants. However, timing parameters (e.g., tINS, tBDD) and power consumption differ - requiring design validation for each specific variant.
71V321SA25PF8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 64-LQFP
- Packaging:
- Tape & Reel (TR)
- 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:
- 3V ~ 3.6V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (14x14)
71V321SA25PF8 FAQ
1.How can I place an order for 71V321SA25PF8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71V321SA25PF8 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 71V321SA25PF8 reliable?
The price and inventory of 71V321SA25PF8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71V321SA25PF8 is usually 5 days.
3.What payment methods are accepted for 71V321SA25PF8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71V321SA25PF8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71V321SA25PF8?
71V321SA25PF8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71V321SA25PF8 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 71V321SA25PF8?
For technical support, including 71V321SA25PF8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71V321SA25PF8 requirements.
6.How does Aetrix verify that 71V321SA25PF8 is sourced from the original manufacturer or authorized distributors?
All 71V321SA25PF8 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 71V321SA25PF8 meets industry standards.
7.What is the process for return or replacement of 71V321SA25PF8?
All 71V321SA25PF8 units undergo pre-shipment inspection (PSI). If there is an issue with 71V321SA25PF8, 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 71V321SA25PF8 part is unused and in its original packaging.
Return procedure for 71V321SA25PF8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71V321SA25PF8 Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
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24LC01BT-I/OT
Microchip Technology
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M24C02-FMC6TG
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AT24CS02-SSHM-T
Microchip Technology
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93LC46BT-I/OT
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AT24C04C-SSHM-T
Microchip Technology
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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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