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Renesas 71321LA35TFI
- Part No.:
- 71321LA35TFI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA35TFI.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,706
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Product details
Overview
IDT71321LA35TFI 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 delivers 35 ns max read cycle time, 2V battery-backed data retention, industrial temperature operation (–40°C to +85°C), and supports fully asynchronous dual-port access - enabling use in redundant controller synchronization and shared-memory multiprocessing.
For engineers reviewing the IDT71321LA35TFI datasheet, IDT71321LA35TFI pinout, IDT71321LA35TFI application, or IDT71321LA35TFI equivalent, key selection criteria include its master-mode BUSY arbitration, interrupt mailbox addressing (7FEh/7FFh), low-power LA variant standby current (1 µA typical), and compatibility with 52-pin STQFP packaging for space-constrained industrial control modules.
Technical Context
The IDT71321LA35TFI implements on-chip port arbitration logic that resolves contention via address- and CE-based BUSY flag generation - not R/W state - ensuring deterministic write inhibition when both ports access the same address. Its two independent ports feature separate control (CEL/CER, OEL/OER, R/WL/R/WR), address (A0L–A10L / A0R–A10R), and bidirectional I/O (I/O0L–I/O7L / I/O0R–I/O7R) sets, enabling full-speed concurrent reads/writes without external logic.
Interrupt functionality uses dedicated mailbox addresses: writing to 7FEh (right port) asserts INTL; writing to 7FFh (left port) asserts INTR. Both flags are cleared by reading the respective address with OE active. The LA variant adds 2V data retention capability, with ICCDR ≤ 1.5 mA at VCC = 2.0 V, supporting battery-backed operation during main power loss.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), dual-port SRAM with independent left/right address/data paths |
| Access Time (tRC) | 35 ns max - guarantees sub-29 MHz sustained read/write throughput per port |
| Supply Voltage | 5.0 V ±10% - TTL-compatible single supply; no level-shifting required in 5V systems |
| Data Retention | 2.0 V min - enables backup from coin cell or supercapacitor during AC failure |
| Standby Current (ISB3) | 0.2 µA typical - ultra-low leakage in full CMOS standby mode with CE high |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, motor drives, and railway electronics |
| Interrupt Latency (tINS) | 25 ns max - ensures sub-40 MHz processor can detect mailbox writes within one clock cycle |
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 (000h–7FFh) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access (000h–7FFh) |
| 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; high-impedance when OER = VIH or CER = VIH |
| CEL / CER | Chip enable (left/right) | Active-low enables port; controls power-down mode (ISB1–ISB4) |
| OEL / OER | Output enable (left/right) | Active-low enables I/O drivers; disables outputs without disabling port |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines direction of I/O bus |
| INTL / INTR | Interrupt flags (open-drain) | Asserted low on mailbox write (7FEh/7FFh); require external pull-up |
| BUSYL / BUSYR | BUSY arbitration signals | BUSYL/BUSYR are open-drain outputs on IDT71321LA35TFI; require 270Ω pull-up |
| VCC / GND | Power and ground | All VCC pins must be decoupled locally; all GND pins tied to common plane |
Key Features
| Feature | Design Value |
|---|---|
| Master-mode BUSY arbitration | Hardware-enforced write blocking on address collision - eliminates need for software polling or external logic |
| Dual interrupt mailboxes | Fixed-location (7FEh/7FFh), user-writable 8-bit registers for interprocessor signaling without shared register overhead |
| 2V data retention | Preserves memory contents during main power loss using backup battery or capacitor - validated at TA = +25°C |
| Asynchronous dual-port operation | Independent timing per port; no clock required - simplifies integration with heterogeneous processors (e.g., ARM + DSP) |
| Low-power LA variant | 1 µA typical ISB1 (TTL-level standby) and 0.2 µA ISB3 (CMOS-level standby) - extends battery life in portable diagnostics tools |
Applications
| Industrial PLC Redundancy | Avionics Data Crossfeed |
|---|---|
Use Scenario: Dual-CPU safety-critical programmable logic controller requiring synchronized state exchange between primary and backup CPUs. IC Role / Device Role / Timing Role: IDT71321LA35TFI acts as shared memory hub with BUSY arbitration preventing simultaneous writes to identical I/O mapping registers. Use Value: Eliminates race conditions during failover; 35 ns access enables <100 ns state update latency between controllers. |
Use Scenario: Flight management system exchanging sensor fusion results between navigation and guidance computers. IC Role / Device Role / Timing Role: IDT71321LA35TFI serves as interrupt-driven mailbox with 7FEh/7FFh locations triggering cross-processor interrupts upon new data arrival. Use Value: Reduces interprocessor latency to ≤25 ns; 2V retention preserves last valid attitude solution during brief power interruption. |
| Medical Imaging Buffer | Test Equipment Pattern Memory |
Use Scenario: Real-time MRI image reconstruction pipeline buffering raw k-space data between acquisition FPGA and processing CPU. IC Role / Device Role / Timing Role: IDT71321LA35TFI provides non-blocking dual-port access: FPGA writes raw data while CPU reads processed frames. Use Value: 35 ns tRC sustains >28 MB/s sustained bandwidth per port; low ISB3 minimizes thermal load in sealed enclosures. |
Use Scenario: Automated test equipment storing stimulus/response patterns for semiconductor wafer probing. IC Role / Device Role / Timing Role: IDT71321LA35TFI functions as pattern memory with interrupt-triggered pattern switching between test sequences. Use Value: Mailbox interrupts reduce pattern change latency to <30 ns; 52-pin STQFP fits high-density probe card layouts. |
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-35AXC | 3.3V core, 35 ns, 2K × 16 organization; no built-in BUSY arbitration or interrupt logic | Requires external logic for contention resolution; better suited for wide-bus systems needing 16-bit data path | Select if migrating to 3.3V domain and adding custom arbitration; not drop-in compatible |
| IDT71421LA35TFI | SLAVE-only variant; BUSY pins are inputs only; no on-chip arbitration logic; identical timing and retention | Used only in MASTER/SLAVE width-expansion configurations (e.g., 16-bit bus with IDT71321LA35TFI as master) | Select only as companion SLAVE in multi-chip 16+ bit memory systems - never standalone replacement |
Compared with CY7C024AV-35AXC and IDT71421LA35TFI, the IDT71321LA35TFI uniquely integrates master-mode arbitration and interrupt mailboxes in a 5V, 2K×8 footprint - making it irreplaceable for compact, self-contained dual-processor synchronization where external logic area and BOM count are constrained.
Availability
IDT71321LA35TFI is available at Aetrix Electronics and suitable for industrial PLC redundancy, avionics crossfeed, and medical imaging buffer applications requiring stable component supply across extended product lifecycles.
Supply support for IDT71321LA35TFI 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, designs high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.
The IDT71321LA35TFI belongs to IDT's legacy dual-port SRAM family engineered specifically for deterministic interprocessor communication in real-time control systems - emphasizing hardware arbitration, low-latency interrupts, and battery-backed reliability.
FAQ
What is the function of BUSYL and BUSYR on the IDT71321LA35TFI?
BUSYL and BUSYR are open-drain output signals on the IDT71321LA35TFI used for hardware arbitration. When asserted low, they inhibit writes to the corresponding port during address contention. Each requires a 270 Ω external pull-up resistor to VCC. These signals are outputs only on the MASTER IDT71321LA35TFI - unlike the SLAVE IDT71421LA35TFI where BUSY pins serve as inputs.
Does the IDT71321LA35TFI support true simultaneous read/write operations on both ports?
Yes - the IDT71321LA35TFI supports fully asynchronous, independent read and write operations on left and right ports. However, if both ports access the same memory address, BUSY arbitration blocks the later-arriving write until the first completes. Reads remain unaffected, and no data corruption occurs due to the on-chip contention resolution logic.
How do the interrupt mailboxes (7FEh and 7FFh) operate in the IDT71321LA35TFI?
In the IDT71321LA35TFI, writing to address 7FEh (with CER = R/WR = VIL) asserts the INTL flag; writing to 7FFh (with CEL = R/WL = VIL) asserts INTR. Flags are cleared by reading the same address with OE active (OEL or OER = VIL). These locations behave as standard SRAM when interrupts are unused.
What is the minimum VCC required to retain data in the IDT71321LA35TFI during power loss?
The IDT71321LA35TFI guarantees data retention down to VCC = 2.0 V, as specified in the LA variant's data retention characteristics. At this voltage, ICCDR is ≤1.5 mA (typical), enabling reliable backup from a CR2032 coin cell or low-leakage supercapacitor without external regulators.
Is the IDT71321LA35TFI pin-compatible with faster or slower speed grades in the same family?
Yes - all IDT71321Xxx variants (e.g., IDT71321LA20TFI, IDT71321LA55TFI) share identical 52-pin STQFP pinouts and DC characteristics. Only AC timing parameters differ (e.g., tRC = 20/35/55 ns). System-level timing margins must be re-verified when substituting speed grades, but PCB layout and firmware remain unchanged.
71321LA35TFI 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:
- 35ns
- Access Time:
- 35 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 (10x10)
71321LA35TFI FAQ
1.How can I place an order for 71321LA35TFI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA35TFI 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 71321LA35TFI reliable?
The price and inventory of 71321LA35TFI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA35TFI is usually 5 days.
3.What payment methods are accepted for 71321LA35TFI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA35TFI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA35TFI?
71321LA35TFI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA35TFI 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 71321LA35TFI?
For technical support, including 71321LA35TFI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA35TFI requirements.
6.How does Aetrix verify that 71321LA35TFI is sourced from the original manufacturer or authorized distributors?
All 71321LA35TFI 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 71321LA35TFI meets industry standards.
7.What is the process for return or replacement of 71321LA35TFI?
All 71321LA35TFI units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA35TFI, 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 71321LA35TFI part is unused and in its original packaging.
Return procedure for 71321LA35TFI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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