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Renesas 71321LA20TF8
- Part No.:
- 71321LA20TF8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA20TF8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,350
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Product details
Overview
IDT71321LA20TF8 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 20 ns max read cycle time, supports 5 V ±10% TTL-compatible operation, features battery-backed data retention down to 2 V, and operates across the industrial temperature range (–40°C to +85°C). It is used in dual-CPU arbitration systems requiring deterministic port-to-port handshaking.
For engineers reviewing the IDT71321LA20TF8 datasheet, IDT71321LA20TF8 pinout, IDT71321LA20TF8 application, or IDT71321LA20TF8 equivalent, key selection considerations include its master-mode BUSY output behavior, dual-interrupt flag timing (tINS/tINR), 2V data retention capability, low 1 µA full-standby current (ISB3), and compatibility with IDT71421SLAVE devices in 16-bit+ memory expansions.
Technical Context
The IDT71321LA20TF8 implements fully asynchronous dual-port access with independent left/right control, address, and I/O buses. Its on-chip arbitration logic resolves contention via BUSY flag assertion based solely on chip enable (CEL/CER) and address match - not R/W state - enabling deterministic write inhibition during simultaneous access to identical addresses.
As a MASTER device, it drives open-drain BUSYL/BUSYR outputs (requiring 270 Ω pull-ups) and generates INTL/INTR flags via dedicated mailbox addresses (7FEh/7FFh). It supports both CE-controlled and R/W-controlled write cycles, with tWC = 20 ns and tWP = 15 ns, and includes automatic power-down when CE is deasserted.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16 kbit total capacity |
| Max Read Cycle Time (tRC) | 20 ns - defines minimum interval between successive reads on same port |
| Data Retention Voltage | 2.0 V - enables battery backup operation with guaranteed data hold |
| Full Standby Current (ISB3) | 0.2 mA typ. - ultra-low power mode with CMOS-level inputs disabled |
| Industrial Temp Range | –40°C to +85°C - qualified for harsh-environment industrial control applications |
| Supply Voltage | 4.5 V to 5.5 V - single 5 V ±10% rail, TTL-compatible input thresholds |
| Interrupt Set/Reset Time | tINS = 20 ns max, tINR = 20 ns max - fast mailbox flag response for real-time signaling |
Pinout & Package
Package: 64-pin TQFP (PNG64), 14 mm × 14 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) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access |
| 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 access and disables standby current (ISB1/ISB2) |
| OEL / OER | Output enable (left/right) | Active-low controls I/O drivers; high-Z when deasserted |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines direction of I/O bus |
| BUSYL / BUSYR | Busy flag (output only) | Open-drain outputs indicating port contention; require 270 Ω pull-up |
| INTL / INTR | Interrupt flags (output only) | Active-high flags set by opposite port writing to 7FEh (INTL) or 7FFh (INTR) |
| VCC / GND | Power supply pins | Multiple VCC/GND pairs ensure stable operation and low noise at 20 ns speed |
Key Features
| Feature | Design Value |
|---|---|
| Master-mode BUSY arbitration | Hardware-based port conflict resolution using CE + address match - no software overhead or external logic required |
| Dual-interrupt mailbox addressing | Fixed 7FEh (left flag) and 7FFh (right flag) locations enable zero-latency interprocessor signaling |
| 2 V data retention | Preserves memory contents during main power loss using backup battery - critical for fault-tolerant systems |
| Ultra-low ISB3 standby current | 0.2 mA typical with CMOS-level inputs ensures minimal power draw in deep-sleep modes |
| 64-pin TQFP package | Standard footprint compatible with automated SMT assembly and thermal management in dense PCB layouts |
Applications
| Real-Time Dual-Processor Communication | Industrial PLC Memory Coherency |
|---|---|
Use Scenario: Two independent CPUs share status, commands, and sensor data via shared memory without software locks. IC Role / Device Role / Timing Role: IDT71321LA20TF8 acts as MASTER arbiter, asserting BUSYL/BUSYR to prevent simultaneous writes and generating INTL/INTR for event-driven synchronization. Use Value: Eliminates race conditions and software polling; 20 ns tRC enables sub-microsecond message exchange between processors. |
Use Scenario: Programmable Logic Controller uses dual-CPU architecture where one CPU handles I/O scanning and the other runs control algorithms. IC Role / Device Role / Timing Role: IDT71321LA20TF8 provides deterministic, hardware-enforced memory coherency between scan and execution cores under industrial temperature stress. Use Value: Guarantees atomic updates to shared variables (e.g., process setpoints) even during voltage droop or transient noise. |
| Redundant Avionics Data Buffering | Medical Imaging Frame Synchronization |
Use Scenario: Fault-tolerant flight control system buffers sensor fusion results between primary and backup computing channels. IC Role / Device Role / Timing Role: IDT71321LA20TF8 serves as dual-port buffer with 2 V data retention, preserving last-known-good state during power switchover. Use Value: Enables seamless failover with zero data loss; ISB3 < 0.2 mA extends battery runtime during main power outage. |
Use Scenario: MRI or CT scanner synchronizes image acquisition (front-end FPGA) and reconstruction (host processor) via shared frame buffers. IC Role / Device Role / Timing Role: IDT71321LA20TF8 provides low-latency, contention-free access to pixel data blocks using interrupt-driven mailbox protocol. Use Value: Reduces frame latency by >30% vs. software-managed semaphores; tINS ≤ 20 ns ensures precise timing alignment. |
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 CY7C136-25JC | 25 ns access, no built-in BUSY arbitration logic; requires external glue logic for master/slave coordination | Lacks integrated interrupt mailboxes (7FEh/7FFh); software-managed signaling only | Choose when legacy design reuse outweighs need for hardware arbitration and interrupts |
| IDT71421LA20TF8 | SLAVE-only variant; BUSY pins are inputs (not outputs); no on-chip arbitration logic | Must be paired with IDT71321LA20TF8 in width-expanded systems; cannot operate standalone as master | Use only as companion SLAVE in 16-bit+ memory configurations; not a functional replacement |
Compared with CY7C136-25JC and IDT71421LA20TF8, the IDT71321LA20TF8 uniquely integrates master-mode BUSY arbitration, dual-interrupt mailboxes, and 2 V data retention - eliminating external logic, reducing BOM count, and enabling deterministic real-time interprocessor communication in a single IC.
Availability
IDT71321LA20TF8 is available at Aetrix Electronics and suitable for industrial automation, avionics subsystems, and medical imaging equipment requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for IDT71321LA20TF8 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 sensor signal conditioning solutions for high-performance computing and communications.
The IDT71321LA20TF8 belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time embedded systems where hardware arbitration and low-power data retention are critical.
FAQ
What is the function of the BUSY pins on the IDT71321LA20TF8?
The BUSYL and BUSYR pins on the IDT71321LA20TF8 are open-drain outputs that signal port contention during simultaneous access to the same memory address. When asserted (pulled low), they inhibit writes on the respective port. Each requires a 270 Ω pull-up resistor to VCC. These pins are active only in MASTER configuration - unlike the SLAVE IDT71421LA20TF8, where BUSY is an input.
Does the IDT71321LA20TF8 support true dual-port concurrent read/write operations?
Yes - the IDT71321LA20TF8 supports fully asynchronous, independent read and write operations on left and right ports simultaneously. However, if both ports access the same address, hardware arbitration asserts BUSYL or BUSYR to block the later-arriving write, ensuring data integrity. Reads remain unaffected during contention.
How does the interrupt functionality work in the IDT71321LA20TF8?
The IDT71321LA20TF8 uses fixed mailbox addresses: writing to 7FEh (hex) from the right port sets the INTL flag; writing to 7FFh from the left port sets the INTR flag. The corresponding port clears its flag by reading that same address. This enables lock-free, hardware-triggered interprocessor messaging with tINS ≤ 20 ns and tINR ≤ 20 ns timing.
What is the significance of the "LA" suffix in IDT71321LA20TF8?
The "LA" denotes the low-power, battery-backed version of the IDT71321. It guarantees data retention at VCC = 2.0 V (vs. SA versions requiring ≥ 4.5 V), with full-standby current ISB3 = 0.2 mA typical. This enables use in systems requiring nonvolatile memory hold during main power interruption - a key differentiator from SA-grade parts.
Can the IDT71321LA20TF8 be used without external pull-up resistors on BUSY and INT pins?
No - the BUSYL, BUSYR, INTL, and INTR pins on the IDT71321LA20TF8 are open-drain outputs and require external pull-up resistors to function correctly. The datasheet specifies 270 Ω for BUSY/INT signals. Omitting these resistors will result in undefined logic levels and failure of arbitration or interrupt signaling.
71321LA20TF8 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:
- 20ns
- Access Time:
- 20 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (10x10)
71321LA20TF8 FAQ
1.How can I place an order for 71321LA20TF8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA20TF8 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 71321LA20TF8 reliable?
The price and inventory of 71321LA20TF8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA20TF8 is usually 5 days.
3.What payment methods are accepted for 71321LA20TF8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA20TF8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA20TF8?
71321LA20TF8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA20TF8 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 71321LA20TF8?
For technical support, including 71321LA20TF8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA20TF8 requirements.
6.How does Aetrix verify that 71321LA20TF8 is sourced from the original manufacturer or authorized distributors?
All 71321LA20TF8 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 71321LA20TF8 meets industry standards.
7.What is the process for return or replacement of 71321LA20TF8?
All 71321LA20TF8 units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA20TF8, 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 71321LA20TF8 part is unused and in its original packaging.
Return procedure for 71321LA20TF8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA20TF8 Tags
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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