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Renesas 71321SA35TF
- Part No.:
- 71321SA35TF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321SA35TF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:2,144
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Product details
Overview
71321SA35TF from Integrated Device Technology is a high-speed 2K × 8 dual-port static RAM with interrupt and BUSY arbitration logic, designed as a MASTER device for interprocessor communication. It delivers 35 ns max read cycle time, operates on single 5V ±10% supply, supports industrial temperature range (–40°C to +85°C), and features two independent asynchronous ports with TTL-compatible I/O - used in real-time embedded control systems requiring concurrent CPU/DSP memory access.
For engineers reviewing the 71321SA35TF datasheet, 71321SA35TF pinout, 71321SA35TF application, or 71321SA35TF equivalent, key selection criteria include its MASTER-only BUSY output capability, port-to-port interrupt mailbox addressing (7FEh/7FFh), 52-pin STQFP package compatibility, and absence of battery backup (LA variant only).
Technical Context
The 71321SA35TF implements fully asynchronous dual-port architecture with separate address/control/I/O buses per port, enabling simultaneous read/write operations without external arbitration logic. Its on-chip arbitration logic responds exclusively to chip enable (CEL/CER) and address match (A0–A10) timing - not R/W state - and asserts open-drain BUSYL/BUSYR outputs requiring 270 Ω pull-up resistors.
Interrupt functionality uses dedicated mailbox addresses: right-port write to 7FFh sets INTR; left-port write to 7FEh sets INTL. Clearing requires read access to the same address with OE enabled. This hardware mailbox mechanism eliminates software polling overhead in tightly coupled multiprocessor systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16 kbit total capacity |
| Access Time (tAA) | 35 ns max - defines minimum address hold before valid data appears |
| Read Cycle Time (tRC) | 35 ns max - governs maximum sustained read throughput (28.6 MHz) |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible single 5V rail, no auxiliary supplies required |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded control environments |
| Power Consumption | Active: 80 mA typ (400 mW); Standby (ISB1): 25 mA typ - enables low-duty-cycle power management |
| Interrupt Addresses | INTL triggered by write to 7FEh; INTR triggered by write to 7FFh - fixed hardware mailbox locations |
Pinout & Package
71321SA35TF is packaged in 52-pin STQFP (PPG52), measuring 10 mm × 10 mm × 1.4 mm, with exposed thermal pad (not electrically connected). Pin 1 marked via corner notch; pins arranged in single perimeter with GND and VCC distributed across multiple locations for noise reduction.
| 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 access and disables internal circuitry for standby current reduction |
| OEL / OER | Output enable (left/right) | Active-low controls I/O drivers; independent of CE for flexible bus sharing |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines data direction during CE/OE assertion |
| BUSYL / BUSYR | BUSY flag (output only) | Open-drain outputs indicating port contention; require 270 Ω pull-up to VCC |
| INTL / INTR | Interrupt flags (output) | Active-high interrupt signals asserted on mailbox writes (7FEh/7FFh) |
| VCC / GND | Power supply | Multiple VCC (pins 18, 27, 40, 47) and GND (pins 21, 33, 45, 52) pins reduce IR drop and EMI |
Key Features
| Feature | Design Value |
|---|---|
| MASTER-only BUSY arbitration | Hardware port conflict detection using CE/address timing - eliminates need for external logic in width-expanded arrays |
| Dual-mailbox interrupt system | Fixed 7FEh (INTL) and 7FFh (INTR) addresses enable deterministic interprocessor signaling without software overhead |
| Asynchronous dual-port operation | Fully independent left/right control paths allow concurrent CPU and DSP access to shared memory without clock domain synchronization |
| Low-power standby modes | ISB1 = 25 mA typ (both ports disabled); ISB3 = 1.0 mA typ (CMOS-level inputs) - supports burst-mode power gating |
| TTL-compatible I/O | VIH = 2.2 V min, VOL = 0.4 V max at 4 mA - interoperable with legacy 5V microcontrollers and FPGAs |
Applications
| Industrial PLC Communication Hub | Real-Time DSP + MCU Shared Memory |
|---|---|
Use Scenario: Two independent processors (PLC main CPU and motion control DSP) share configuration and status data in deterministic cycles. IC Role / Device Role / Timing Role: MASTER dual-port SRAM acts as synchronized memory bridge with hardware BUSY arbitration preventing write collisions during concurrent access. Use Value: Eliminates software semaphore overhead and guarantees atomic mailbox updates via 7FEh/7FFh interrupt triggers - reducing worst-case latency by >3.5 µs vs polled implementation. |
Use Scenario: A TI C6000 DSP offloads FFT computation while an ARM Cortex-M4 handles I/O and scheduling; both require low-latency access to shared sensor buffers. IC Role / Device Role / Timing Role: Asynchronous dual-port interface provides zero-wait-state memory access for both cores without clock domain crossing logic. Use Value: 35 ns tAA enables full 28.6 MHz read throughput per port - sustaining 45.7 MB/s aggregate bandwidth for real-time streaming applications. |
| Avionics Data Concentrator | Medical Imaging Frame Buffer |
Use Scenario: ARINC 429 receiver and MIL-STD-1553B host processor exchange telemetry packets in safety-critical flight control subsystems. IC Role / Device Role / Timing Role: Hardware interrupt mailbox (7FFh/7FEh) delivers packet-ready notifications with sub-25 ns jitter - meeting DO-254 Class C timing budgets. Use Value: Deterministic interrupt assertion replaces unreliable polling loops, improving system response predictability and simplifying certification evidence generation. |
Use Scenario: Ultrasound beamformer FPGA writes raw echo data while ARM-based UI processor reads processed frames for display. IC Role / Device Role / Timing Role: Dual-port SRAM decouples high-speed acquisition (FPGA side) from variable-rate rendering (CPU side) without FIFO bottlenecks. Use Value: Independent CE/OE control per port allows dynamic bandwidth allocation - e.g., prioritizing FPGA writes during acquisition bursts while maintaining UI refresh rates. |
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 access, 100-pin TQFP; no native BUSY arbitration - requires external logic for conflict resolution | Larger memory depth suits buffer-intensive imaging; lacks integrated interrupt mailboxes | Select when >16 kbit capacity is required and board space permits external arbitration circuitry |
| IDT71421SA35TF | SLAVE counterpart; BUSY pins are inputs only; no on-chip arbitration logic; identical speed/package | Used only in MASTER/SLAVE width-expansion configurations - cannot operate standalone as memory controller | Choose only when building 16-bit+ bus systems with 71321SA35TF as MASTER; not a functional substitute |
Compared with CY7C024AV-35AXC and IDT71421SA35TF, the 71321SA35TF uniquely combines MASTER arbitration, interrupt mailboxes, and compact 52-pin STQFP packaging - making it optimal for space-constrained, low-latency interprocessor communication where deterministic conflict resolution is mandatory.
Availability
71321SA35TF is available at Aetrix Electronics and suitable for industrial PLCs, avionics data concentrators, and medical imaging systems requiring stable component supply across extended production lifecycles.
Supply support for 71321SA35TF 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, specializes in high-performance timing, memory interface, and RF solutions for communications and computing infrastructure.
The IDT71321 family was engineered specifically for deterministic interprocessor communication in real-time embedded systems - emphasizing hardware arbitration, low-latency interrupts, and industrial temperature reliability over density or ultra-low power.
FAQ
What is the function of BUSYL and BUSYR on the 71321SA35TF?
BUSYL and BUSYR are open-drain output flags on the 71321SA35TF that indicate port contention when both ports attempt simultaneous access to the same memory location. They require external 270 Ω pull-up resistors to VCC. These signals are asserted only on the MASTER device (71321SA35TF) and serve as hardware write-inhibit indicators - unlike the SLAVE IDT71421 where BUSY pins are inputs. The 71321SA35TF uses CE and address timing (not R/W state) to trigger BUSY, ensuring deterministic arbitration.
Does the 71321SA35TF support battery backup for data retention?
No, the 71321SA35TF does not support battery backup. Battery-backed data retention (down to 2V VCC) is exclusive to the LA variant (e.g., 71321LA35TF). The 'SA' suffix denotes standard active-power operation only, with full standby current (ISB3) of 1.0 mA typical at CMOS-level inputs. For applications requiring nonvolatile retention during main power loss, the LA variant or external backup circuitry must be used - the 71321SA35TF retains data only while powered within its 4.5–5.5 V operating range.
How do the interrupt mailboxes (7FEh and 7FFh) work on the 71321SA35TF?
The 71321SA35TF uses fixed-address hardware mailboxes: writing to 7FFh (hex) with the right port asserts INTR; writing to 7FEh with the left port asserts INTL. Clearing requires reading those same addresses with OE enabled (CEL/OEL = VIL for left; CER/OER = VIL for right). These are true SRAM locations - user data written to them persists until overwritten. The 71321SA35TF interrupt logic operates independently of arbitration and requires no configuration registers, delivering sub-25 ns deterministic flag assertion - critical for hard real-time interprocessor signaling.
Can the 71321SA35TF operate as a standalone dual-port memory without a SLAVE device?
Yes, the 71321SA35TF functions fully as a standalone 2K × 8 dual-port SRAM with complete left/right port control, BUSY arbitration, and interrupt capabilities. Its MASTER designation refers to its ability to drive BUSY outputs and manage width expansion - not dependency on a SLAVE. The IDT71421 is optional and used only when expanding data bus width beyond 8 bits (e.g., 16-bit systems). In standalone mode, the 71321SA35TF provides all dual-port features including independent CE/OE/R/W control, mailbox interrupts, and contention detection without external components.
What package type and pin count does the 71321SA35TF use?
The 71321SA35TF uses a 52-pin STQFP (Small Thin Quad Flat Package) designated PPG52, with dimensions of 10 mm × 10 mm × 1.4 mm and a thermal pad. It is distinct from the 64-pin TQFP variants (PNG64/PPG64) and 52-pin PLCC (PLG52) options in the same family. Pin 1 is located at the top-left corner adjacent to the package notch. This STQFP package offers superior thermal performance and board-space efficiency compared to PLCC, making it suitable for dense industrial PCB layouts where reflow compatibility and thermal management are critical.
71321SA35TF 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (10x10)
71321SA35TF FAQ
1.How can I place an order for 71321SA35TF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321SA35TF 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 71321SA35TF reliable?
The price and inventory of 71321SA35TF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321SA35TF is usually 5 days.
3.What payment methods are accepted for 71321SA35TF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321SA35TF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321SA35TF?
71321SA35TF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321SA35TF 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 71321SA35TF?
For technical support, including 71321SA35TF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321SA35TF requirements.
6.How does Aetrix verify that 71321SA35TF is sourced from the original manufacturer or authorized distributors?
All 71321SA35TF 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 71321SA35TF meets industry standards.
7.What is the process for return or replacement of 71321SA35TF?
All 71321SA35TF units undergo pre-shipment inspection (PSI). If there is an issue with 71321SA35TF, 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 71321SA35TF part is unused and in its original packaging.
Return procedure for 71321SA35TF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321SA35TF Tags
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