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Renesas 71321LA35PF8
- Part No.:
- 71321LA35PF8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA35PF8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,419
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Product details
Overview
71321LA35PF8 from Integrated Device Technology is a high-speed 2K × 8 dual-port static RAM with interrupt logic and BUSY arbitration, designed as a MASTER device for interprocessor communication. It features 35 ns max access time, 1 mW standby power (LA version), 2 V data retention, TTL-compatible 5 V ±10% supply, and operates across –40°C to +85°C industrial temperature range.
For engineers reviewing the 71321LA35PF8 datasheet, 71321LA35PF8 pinout, 71321LA35PF8 application, or 71321LA35PF8 equivalent, key selection criteria include dual-port asynchronous read/write timing, MASTER/SLAVE expansion capability, interrupt mailbox addressing (7FEh/7FFh), BUSY output open-drain drive requirement (270 Ω pull-up), and battery-backed data retention at 2 V.
Technical Context
The 71321LA35PF8 implements fully asynchronous dual-port operation with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves port contention via BUSY flag generation based on chip enable and address match - not R/W state - enabling deterministic write inhibition during simultaneous access to identical addresses.
As a MASTER device, it provides two open-drain BUSY outputs (BUSYL/BUSYR) and two interrupt flags (INTL/INTR), supporting mailbox-based interprocessor signaling using dedicated SRAM locations (7FEh for INTL set, 7FFh for INTR set). The LA variant adds ultra-low-power 2 V data retention mode with ≤100 µA ICCDR.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), fully random-access dual-port array |
| Access Time (max) | 35 ns - defines minimum read cycle time (tRC) for reliable data capture in high-speed bus interfaces |
| Standby Current (ISB3) | 0.2 mA typ. - enables ultra-low-power hold mode when both ports are deselected with CMOS-level inputs |
| Data Retention Voltage | 2.0 V - supports battery backup operation without external regulators; retains data with no active supply |
| Operating Temperature | –40°C to +85°C - qualified for industrial embedded systems requiring extended thermal stability |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible single 5 V ±10% rail; all VCC pins require decoupling |
| Interrupt Mailbox Addresses | 7FEh (set INTL), 7FFh (set INTR) - user-configurable SRAM locations used for hardware-triggered interprocessor signaling |
Pinout & Package
71321LA35PF8 is packaged in a 64-pin STQFP (PPG64), measuring 10 mm × 10 mm × 1.4 mm, with exposed pad for thermal dissipation. Pin functions are validated per IDT DSC-2691 Rev. 17 (September 2019).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left port address inputs | 11-bit address bus for left-side memory access; latched on CE/R/W transitions |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access; independent of left port timing |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit tri-state I/O bus; direction controlled by R/WL and OEL; high-impedance when disabled |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit tri-state I/O bus; electrically isolated from left port; supports concurrent read/write |
| CEL / CER | Chip enable (left/right) | Active-low enables respective port; controls power-down entry (ISB1–ISB4 modes) |
| OEL / OER | Output enable (left/right) | Active-low enables I/O drivers; overrides R/W for tristate control during reads |
| R/WL / R/WR | Read/write control (left/right) | Active-low initiates write; high enables read; determines I/O direction and internal latch timing |
| BUSYL / BUSYR | BUSY flag (open-drain outputs) | Indicates port contention; requires external 270 Ω pull-up; asserts low when opposite port accesses same address |
| INTL / INTR | Interrupt flags (open-drain outputs) | Assert low on mailbox writes (7FEh/7FFh); used for hardware event notification between processors |
| VCC / GND | Power and ground | Multiple VCC/GND pins distributed for noise reduction; all must be connected per layout guidelines |
Key Features
| Feature | Design Value |
|---|---|
| MASTER/SLAVE expandability | Enables seamless 16-bit+ word-width systems using one 71321LA35PF8 MASTER with multiple IDT71421 SLAVEs - no external glue logic required |
| Hardware BUSY arbitration | Resolves simultaneous access conflicts deterministically via address/CE-match detection - eliminates race conditions in real-time interprocessor links |
| Dual interrupt mailboxes | Uses standard SRAM locations 7FEh and 7FFh as hardware-signaled message registers - enables zero-latency, lock-free processor synchronization |
| 2 V data retention | Maintains full memory contents during main power loss using coin-cell or supercap backup - critical for fault-tolerant industrial controllers |
| Industrial temperature support | Guaranteed 35 ns timing and 1 mW standby across –40°C to +85°C - suitable for under-hood automotive ECUs and factory-floor PLCs |
Applications
| Real-Time Interprocessor Communication | Redundant Control System Memory |
|---|---|
Use Scenario: Two microcontrollers exchange status and command data via shared memory without software polling or OS intervention. IC Role / Device Role / Timing Role: 71321LA35PF8 acts as MASTER dual-port RAM with hardware BUSY arbitration and interrupt flags to coordinate atomic mailbox updates. Use Value: Eliminates software locks and reduces inter-core latency to sub-40 ns - essential for deterministic motion control loops. |
Use Scenario: Primary and backup controllers maintain synchronized state in safety-critical infrastructure (e.g., rail signaling, power grid SCADA). IC Role / Device Role / Timing Role: 71321LA35PF8 provides mirrored, asynchronously accessible memory with automatic write conflict resolution via BUSY signals. Use Value: Ensures data coherency during failover events without CPU involvement - meets SIL-2 functional safety requirements. |
| Embedded Data Acquisition Buffer | Industrial PLC Dual-Port Memory Module |
Use Scenario: High-speed ADC streams digitized sensor data into one port while a host processor reads processed results from the other port. IC Role / Device Role / Timing Role: 71321LA35PF8 serves as a non-blocking FIFO buffer with 2K × 8 depth, leveraging independent read/write timing and 35 ns access. Use Value: Sustains continuous 28.6 MB/s throughput (1/35 ns) without DMA stalls or buffer overruns. |
Use Scenario: Programmable Logic Controller uses dual-port RAM to isolate ladder logic execution (right port) from HMI update cycles (left port). IC Role / Device Role / Timing Role: 71321LA35PF8 operates as MASTER in a multi-chip module with SLAVE devices, providing 16-bit-wide memory with centralized BUSY arbitration. Use Value: Enables concurrent scan-cycle execution and operator interface refresh at full PLC clock rate - no cycle-time penalty. |
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 | 32K × 16 organization, 35 ns, 3.3 V core (5 V tolerant I/O), no built-in BUSY arbitration logic | Requires external priority encoder for contention resolution; higher density but larger footprint and voltage translation overhead | Choose when >2K depth is needed and system can implement external arbitration |
| IDT71421LA35PF8 | SLAVE-only dual-port SRAM; identical timing and LA power specs, but BUSY pins are inputs only and no on-chip arbitration logic | Must be paired with a MASTER (e.g., 71321LA35PF8); cannot operate standalone in MASTER role | Use only as expansion slave in width-expanded arrays; not a functional substitute for MASTER functionality |
Compared with CY7C024AV-35AXC and IDT71421LA35PF8, the 71321LA35PF8 uniquely integrates MASTER arbitration, interrupt mailbox logic, and 2 V data retention in a compact 64-pin STQFP - making it optimal for space-constrained, battery-backed, real-time interprocessor designs where deterministic conflict resolution is mandatory.
Availability
71321LA35PF8 is available at Aetrix Electronics and suitable for industrial automation, automotive control units, and telecommunications infrastructure requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for 71321LA35PF8 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 high-performance computing solutions.
The IDT71321/71421 family was engineered specifically for deterministic, low-latency interprocessor communication in real-time embedded systems - emphasizing hardware arbitration, interrupt signaling, and battery-backed reliability over raw density or speed.
FAQ
What is the function of the BUSY pins on the 71321LA35PF8?
The BUSYL and BUSYR pins on the 71321LA35PF8 are open-drain outputs that assert low when the opposite port accesses the same memory address, indicating contention. As a MASTER device, the 71321LA35PF8 uses these signals to inhibit writes during conflict - preventing data corruption without software intervention. Each BUSY pin requires a 270 Ω external pull-up resistor to VCC per IDT DSC-2691 specification.
How does the interrupt functionality work in the 71321LA35PF8?
The 71321LA35PF8 uses SRAM locations 7FEh (hex) and 7FFh to implement hardware interrupts: a write to 7FEh by the right port sets the INTL flag, and a write to 7FFh by the left port sets the INTR flag. Clearing is performed by reading those addresses with appropriate CE/OE asserts. These flags are open-drain outputs and support lock-free interprocessor signaling - a core feature of the 71321LA35PF8 architecture.
Can the 71321LA35PF8 operate with a 3.3 V supply?
No. The 71321LA35PF8 is specified exclusively for 5 V ±10% operation (4.5 V to 5.5 V) and is TTL-compatible. It does not support 3.3 V core or I/O voltage. Attempting 3.3 V operation violates Absolute Maximum Ratings and will result in undefined behavior, failed data retention, or permanent damage. For 3.3 V systems, consider level-shifting or alternative dual-port families such as the IDT70V24/70V25 series.
What package type is used for the 71321LA35PF8?
71321LA35PF8 uses a 64-pin STQFP package designated PPG64 per IDT documentation - measuring 10 mm × 10 mm × 1.4 mm with an exposed thermal pad. This is distinct from the PLCC (PLG52) and TQFP (PNG64) variants. The "PF8" suffix in the part number explicitly denotes the PPG64 STQFP package, confirmed in IDT ordering information tables within DSC-2691.
Does the 71321LA35PF8 support battery backup operation?
Yes. The "LA" suffix indicates the low-power version with verified 2 V data retention capability. When VCC drops to 2.0 V, the 71321LA35PF8 maintains full memory contents with ICCDR ≤ 100 µA (typ.) at +25°C. This mode requires CE pins held high and applies only to the LA variant - the SA version lacks this feature. Data retention is guaranteed but not production-tested per IDT DSC-2691 Table 6.
71321LA35PF8 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:
- 35ns
- Access Time:
- 35 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 (14x14)
71321LA35PF8 FAQ
1.How can I place an order for 71321LA35PF8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA35PF8 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 71321LA35PF8 reliable?
The price and inventory of 71321LA35PF8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA35PF8 is usually 5 days.
3.What payment methods are accepted for 71321LA35PF8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA35PF8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA35PF8?
71321LA35PF8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA35PF8 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 71321LA35PF8?
For technical support, including 71321LA35PF8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA35PF8 requirements.
6.How does Aetrix verify that 71321LA35PF8 is sourced from the original manufacturer or authorized distributors?
All 71321LA35PF8 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 71321LA35PF8 meets industry standards.
7.What is the process for return or replacement of 71321LA35PF8?
All 71321LA35PF8 units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA35PF8, 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 71321LA35PF8 part is unused and in its original packaging.
Return procedure for 71321LA35PF8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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