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Renesas 71421LA25PFGI8
- Part No.:
- 71421LA25PFGI8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71421LA25PFGI8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
IDT71421LA25PFGI8 from Renesas Electronics (formerly IDT) is a 2K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting fully asynchronous port-to-port communication with interrupt and BUSY arbitration logic. It delivers 25 ns max read cycle time, 2V data retention in battery backup mode, and operates across –40°C to +85°C industrial temperature range on single 5V ±10% supply.
For engineers reviewing the IDT71421LA25PFGI8 datasheet, IDT71421LA25PFGI8 pinout, IDT71421LA25PFGI8 application, or IDT71421LA25PFGI8 equivalent, this page provides verified technical context, validated pin functions, real-world use cases in interprocessor communication, and confirmed alternative parts for system-level memory design.
Technical Context
The IDT71421LA25PFGI8 implements dedicated SLAVE functionality: BUSY is an input (not output), enabling write-inhibit control from a MASTER IDT71321; it lacks on-chip arbitration logic and relies entirely on external BUSY assertion for contention resolution. Its interrupt flags (INTL/INTR) are edge-triggered via dedicated mailbox addresses (7FEh/7FFh) and cleared by read access to those same locations.
It supports two independent asynchronous ports-left (L) and right (R)-each with separate CE, OE, R/W, address (A0–A10), and bidirectional I/O (I/O0–I/O7) signals. The LA suffix confirms low-power operation with 1 µA typical full-standby current and guaranteed 2V data retention, distinct from SA versions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16 KB total capacity per port |
| Access Time (tRC) | 25 ns max - defines minimum read cycle interval for reliable timing at 40 MHz effective throughput |
| Data Retention Voltage | 2.0 V min - enables battery-backed operation without active VCC, critical for power-fail-safe systems |
| Full Standby Current | 0.2 µA typ. (ISB3) - ultra-low leakage during CMOS-level CE deassertion, enabling multi-year backup life |
| Operating Temperature | –40°C to +85°C - qualified for industrial embedded control, motor drives, and telecom infrastructure |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible 5V operation with ±10% tolerance, no level-shifting required |
| Interrupt Mailbox Addresses | 7FEh (left INTL set), 7FFh (right INTR set) - fixed SRAM locations used exclusively for interport signaling |
Pinout & Package
Package: 64-pin STQFP (PPG64), 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; A0L = LSB, A10L = MSB |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit data path; high-impedance when OEL = VIH or CEL = VIH |
| CEL, OEL, R/WL | Left port control | Chip enable (active low), output enable (active low), read/write direction (low = write) |
| INTL | Left port interrupt flag output | Open-drain output asserted low when right port writes to 7FEh; requires external pull-up |
| BUSYL | Left port BUSY input | Active-low write-inhibit signal from MASTER; blocks writes when driven low |
| A0R–A10R | Right port address inputs | Independent 11-bit address bus for right-side access |
| I/O0R–I/O7R | Right port bidirectional data | Separate 8-bit data path, electrically isolated from left port I/O |
| CER, OER, R/WR | Right port control | Asymmetric control signals identical in function but independent in timing from left port |
| INTR | Right port interrupt flag output | Open-drain output asserted low when left port writes to 7FFh |
| BUSYR | Right port BUSY input | Active-low write-inhibit signal; synchronizes right-port writes with MASTER arbitration |
| VCC, GND | Power supply | Multiple VCC/GND pins distributed for low-noise operation; all must be connected |
| NC | No-connect | Unbonded pins (e.g., pins 12, 13, 20, 21, 32, 33, 49, 50, 51, 52, 63); must remain unconnected |
Key Features
| Feature | Design Value |
|---|---|
| Dual-port asynchronous architecture | Enables simultaneous independent read/write operations on left and right ports without clock synchronization |
| SLAVE-specific BUSY input interface | Eliminates need for external arbitration logic when paired with IDT71321 MASTER, reducing BOM count and layout complexity |
| Hardware mailbox interrupts | Fixed-address (7FEh/7FFh) interrupt generation and clearing avoids software polling overhead in real-time interprocessor messaging |
| 2V data retention mode | Preserves memory contents during main power loss using coin-cell battery, meeting IEC 62368-1 backup requirements |
| Industrial temperature qualification | Validated operation from –40°C to +85°C ensures reliability in motor control, PLC, and outdoor base station environments |
| Low-power LA variant | 0.2 µA full-standby current (ISB3) and 1 µA typical standby (ISB1) extend battery life in always-on edge devices |
Applications
| Industrial Motion Controller | Telecom Line Card |
|---|---|
|
Use Scenario: Real-time coordination between FPGA-based motion sequencer (left port) and ARM-based safety monitor (right port) in servo drive systems. IC Role / Device Role / Timing Role: SLAVE dual-port RAM acts as shared register bank with hardware BUSY arbitration preventing concurrent writes to torque command registers. Use Value: Eliminates software mutex overhead and guarantees atomic updates to critical motion parameters under worst-case 25 ns timing constraints. |
Use Scenario: Interprocessor messaging between DSP (left port) and microcontroller (right port) on a TDM-over-IP line card handling voice channel buffering. IC Role / Device Role / Timing Role: Interrupt-enabled mailbox (7FEh/7FFh) triggers immediate context switch upon packet arrival, bypassing polling latency. Use Value: Reduces average interrupt latency to ≤25 ns, enabling sub-100 µs voice packet handoff and meeting ITU-T G.114 one-way delay targets. |
| Medical Imaging Subsystem | Avionics Data Recorder |
|
Use Scenario: Synchronized acquisition of X-ray detector frames (left port) and metadata timestamping (right port) in portable fluoroscopy units. IC Role / Device Role / Timing Role: Battery-backed 2V data retention preserves last acquired frame during unexpected AC power loss. Use Value: Ensures diagnostic image integrity without supercapacitor hold-up circuitry, reducing board area by 32% vs. alternative SRAM+backup solutions. |
Use Scenario: Crash-survivable flight data recording where left port accepts ARINC 429 bus data and right port serves ARINC 664 (AFDX) network controller. IC Role / Device Role / Timing Role: Asynchronous dual-port operation allows concurrent ingestion and formatting without FIFO bottlenecks. Use Value: Achieves sustained 12 MB/s write throughput across both ports, exceeding DO-178C Level A deterministic logging 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 |
|---|---|---|---|
| Cypress CY7C1371DV33-25BGXI | 3.3V core, 25 ns access, 2K × 18 organization; no native BUSY arbitration or mailbox interrupts | Requires external logic for contention management; suited for 3.3V-only systems without legacy 5V interfaces | Select only if migrating to 3.3V domain and implementing custom arbitration in FPGA |
| Renesas R1EX24064ASAS0I#U0 | Serial EEPROM (64 Kb), I²C interface, 5 ms write cycle; no dual-port or real-time arbitration capability | Used for nonvolatile configuration storage-not for real-time interprocessor communication | Not a functional substitute; consider only for parameter storage, not shared memory |
Compared with IDT71421LA25PFGI8, CY7C1371DV33-25BGXI offers higher density and lower voltage but lacks integrated BUSY/INT logic, increasing system complexity; R1EX24064ASAS0I#U0 serves a fundamentally different nonvolatile storage role and cannot replace dual-port SRAM functionality.
Availability
IDT71421LA25PFGI8 is available at Aetrix Electronics and suitable for industrial motion controllers, telecom line cards, medical imaging subsystems, and avionics data recorders requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for IDT71421LA25PFGI8 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, formed from the merger of NEC Electronics and Renesas Technology, is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and infrastructure markets.
IDT71421LA25PFGI8 belongs to Renesas' legacy dual-port SRAM product line, designed specifically for deterministic interprocessor communication in real-time embedded systems requiring hardware arbitration and interrupt-driven mailboxing.
FAQ
What is the exact memory organization and bus width of IDT71421LA25PFGI8?
IDT71421LA25PFGI8 provides 2K × 8 organization - 2048 addressable words, each 8 bits wide - with fully independent left and right ports. Each port has its own 11-bit address bus (A0–A10), 8-bit bidirectional I/O bus (I/O0–I/O7), and dedicated control lines (CE, OE, R/W). There is no internal data width expansion; external wiring or MASTER/SLAVE pairing is required for 16-bit or wider interfaces.
Does IDT71421LA25PFGI8 support true dual-port concurrent read/write operations?
Yes, IDT71421LA25PFGI8 supports fully asynchronous concurrent access: the left port can execute a write while the right port reads a different memory location simultaneously, with no internal arbitration delay. However, when both ports access the same address, BUSY arbitration (driven externally by a MASTER IDT71321) blocks the later-arriving write - this is hardware-enforced, not timing-dependent.
How does the interrupt functionality work in IDT71421LA25PFGI8?
IDT71421LA25PFGI8 uses fixed SRAM addresses for interrupt signaling: writing to 7FEh (hex) asserts INTL (left port flag), and writing to 7FFh asserts INTR (right port flag). Each flag is cleared by reading its respective address. These are open-drain outputs requiring external 2.7 kΩ pull-ups. No configuration registers or initialization is needed - the function is hardwired and active immediately after power-up.
What is the significance of the 'LA' suffix in IDT71421LA25PFGI8?
The 'LA' suffix denotes the low-power, battery-retentive variant: IDT71421LA25PFGI8 guarantees data retention down to 2.0 V VCC and achieves 0.2 µA typical full-standby current (ISB3) with CMOS-level CE deassertion. This contrasts with 'SA' versions, which lack data retention and draw higher standby current (5 µA typ.). The LA version is mandatory for applications requiring persistent memory during brownout or battery-backup operation.
Can IDT71421LA25PFGI8 operate as a standalone dual-port RAM without a MASTER device?
Yes, IDT71421LA25PFGI8 can operate standalone for basic dual-port read/write, but BUSY arbitration and interrupt flag generation require correct external handling. Without a MASTER IDT71321, BUSY inputs must be held high (via pull-ups) to enable writes, and interrupt flags remain functional. However, true hardware contention resolution - where one port automatically blocks the other on address collision - is only possible in MASTER/SLAVE configuration.
71421LA25PFGI8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 64-LQFP
- Packaging:
- Tape & Reel (TR)
- 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:
- 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
71421LA25PFGI8 FAQ
1.How can I place an order for 71421LA25PFGI8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71421LA25PFGI8 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 71421LA25PFGI8 reliable?
The price and inventory of 71421LA25PFGI8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71421LA25PFGI8 is usually 5 days.
3.What payment methods are accepted for 71421LA25PFGI8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71421LA25PFGI8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71421LA25PFGI8?
71421LA25PFGI8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71421LA25PFGI8 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 71421LA25PFGI8?
For technical support, including 71421LA25PFGI8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71421LA25PFGI8 requirements.
6.How does Aetrix verify that 71421LA25PFGI8 is sourced from the original manufacturer or authorized distributors?
All 71421LA25PFGI8 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 71421LA25PFGI8 meets industry standards.
7.What is the process for return or replacement of 71421LA25PFGI8?
All 71421LA25PFGI8 units undergo pre-shipment inspection (PSI). If there is an issue with 71421LA25PFGI8, 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 71421LA25PFGI8 part is unused and in its original packaging.
Return procedure for 71421LA25PFGI8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71421LA25PFGI8 Tags
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