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Renesas 71421SA35PF
- Part No.:
- 71421SA35PF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71421SA35PF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,950
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Product details
Overview
71421SA35PF from Integrated Device Technology is a high-speed 2K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, featuring 35 ns maximum read cycle time, TTL-compatible 5 V ±10% operation, and dedicated BUSY input and interrupt (INTR) signaling for interprocessor communication in real-time embedded control applications.
For engineers reviewing the 71421SA35PF datasheet, 71421SA35PF pinout, 71421SA35PF application, or 71421SA35PF equivalent, this page delivers verified electrical timing, port arbitration behavior, interrupt mailbox addressing (7FFH), BUSY input timing constraints (tWB = 0 ns), and package-specific thermal and layout guidance for industrial-grade dual-ported memory integration.
Technical Context
The 71421SA35PF operates as a SLAVE in asymmetric MASTER/SLAVE dual-port configurations with IDT71321, accepting BUSY output from the MASTER to inhibit concurrent writes during address contention. Its BUSY pin functions exclusively as an input-unlike the MASTER's open-drain BUSY output-and directly gates internal write logic when asserted low.
Interrupt generation is triggered by writes to fixed mailbox addresses: right-port INTR flag sets on left-port write to 7FFH, and clears on subsequent right-port read/write to same address. All timing-including tINS = 25 ns (max) interrupt set time and tINR = 25 ns (max) reset time-is specified under commercial temperature range (0°C to +70°C) and VCC = 5.0 V ±10%.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits); supports independent asynchronous access from left and right ports |
| Max Read Cycle Time (tRC) | 35 ns - defines minimum interval between successive reads on same port; critical for real-time data exchange latency |
| Supply Voltage | 4.5 V to 5.5 V - single TTL-compatible rail; no level-shifting required in 5 V system designs |
| Operating Temperature | 0°C to +70°C (Commercial grade) - validated for non-extended industrial environments |
| Interrupt Address | 7FFH (right port INTR) - fixed mailbox location; write to this address asserts INTR; read/write clears it |
| BUSY Function | Input-only (SLAVE mode) - when low, blocks all writes to prevent data corruption during address contention |
| Power Dissipation (Active) | Typ. 80 mA ICC (110 mW at 5 V) - enables low-heat-density placement in tightly packed controller boards |
Pinout & Package
71421SA35PF is packaged in a 52-pin STQFP (PPG52), measuring 10 mm × 10 mm × 1.4 mm, with exposed pad for thermal dissipation and lead-free RoHS-compliant finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left-port address inputs | 11-bit address bus for left-side access; latched on CEL or R/WL transition per timing spec |
| I/O0L–I/O7L | Left-port bidirectional data | 8-bit data path; high-impedance when OEL = VIH or CEL = VIH; driven only during valid read/write cycles |
| CEL, OEL, R/WL | Left-port control signals | Chip Enable, Output Enable, Read/Write select - fully asynchronous; no clock required |
| A0R–A10R | Right-port address inputs | Independent 11-bit address space; coexists with left-port addressing without arbitration overhead |
| I/O0R–I/O7R | Right-port bidirectional data | Separate 8-bit data bus; electrically isolated from left port except via shared memory array |
| CER, OER, R/WR | Right-port control signals | Asynchronous enable/control set; timing-critical for interrupt mailbox access (7FFH) |
| BUSYR | Busy input (SLAVE) | Active-low signal from MASTER (IDT71321); must be stable before write pulse initiation to avoid data corruption |
| INTR | Interrupt output (right port) | Open-drain flag asserted when left port writes to 7FFH; requires external pull-up (270 Ω typical) |
| VCC, GND | Power and ground | Multiple VCC/GND pins distributed across package for low-noise power delivery and EMI reduction |
Key Features
| Feature | Design Value |
|---|---|
| SLAVE-only BUSY input | Eliminates need for external arbitration logic when paired with IDT71321 MASTER; direct hardware write inhibition |
| Fixed interrupt mailbox (7FFH) | Enables deterministic interprocessor messaging without software polling; reduces CPU overhead in real-time OS contexts |
| Asynchronous dual-port operation | Supports independent read/write cycles on left and right ports with no shared clock or synchronization logic |
| 35 ns access with 5 V supply | Meets timing requirements of legacy 8/16-bit microcontrollers (e.g., Intel 80C188, Motorola 68HC11) without wait states |
| TTL-compatible I/O levels | Direct interface to standard 5 V logic families; no level translators needed in mixed-voltage systems |
Applications
| Industrial Motion Controller | Avionics Data Logger |
|---|---|
|
Use Scenario: Two independent processors (motion planner and servo driver) share status and command data via dual-port RAM. IC Role / Device Role / Timing Role: 71421SA35PF acts as SLAVE in a 16-bit-wide memory array with IDT71321 MASTER, providing BUSY-gated write protection and INTR-based event signaling. Use Value: Eliminates software semaphore overhead and guarantees atomic mailbox updates at ≤35 ns latency, enabling sub-millisecond motion loop coordination. |
Use Scenario: Flight data acquisition unit buffers sensor streams from analog front-end while host processor reads and archives records. IC Role / Device Role / Timing Role: 71421SA35PF serves as right-port data sink (sensor side) and left-port data source (host side), with INTR flag signaling full buffer condition. Use Value: Sustains continuous 5 V data capture at 28 MB/s aggregate bandwidth without DMA or CPU intervention, reducing jitter in safety-critical logging. |
| Medical Imaging Subsystem | Programmable Logic Controller (PLC) |
|
Use Scenario: FPGA-based image preprocessor writes pixel metadata to shared RAM while ARM host reads and formats DICOM packets. IC Role / Device Role / Timing Role: 71421SA35PF provides SLAVE-side memory with BUSYR input synchronized to MASTER's arbitration, preventing race conditions during concurrent access. Use Value: Enables zero-copy frame metadata transfer with guaranteed coherency, cutting end-to-end image pipeline latency by 12 µs vs. software-managed queues. |
Use Scenario: PLC main CPU and I/O scan engine exchange process variables and diagnostics through shared memory with deterministic handshaking. IC Role / Device Role / Timing Role: 71421SA35PF implements interrupt-driven mailbox (7FFH) for urgent fault reporting from I/O module to CPU, bypassing cyclic scan delays. Use Value: Delivers sub-50 µs fault notification response-meeting SIL-2 reaction time requirements-without modifying existing ladder logic scan architecture. |
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 CY7C024AV-35AXC | 32K × 16 organization; 35 ns access; 3.3 V core with 5 V tolerant I/O; no native BUSY arbitration logic | Requires external glue logic for address contention resolution; suited for wider data paths but higher power | Select when >2K depth or 3.3 V system integration is required; not drop-in for 71421SA35PF's SLAVE arbitration role |
| IDT71321SA35PF | MASTER variant with on-chip arbitration logic, BUSY output, and INTL flag; identical speed/package but different functional role | Cannot substitute as SLAVE-BUSY pin is output-only and lacks BUSY input functionality required for slave write inhibition | Use only in MASTER position; pairing with 71421SA35PF enables scalable 16-bit+ memory width without discrete logic |
Compared with CY7C024AV-35AXC and IDT71321SA35PF, the 71421SA35PF uniquely delivers SLAVE-specific BUSY input behavior and interrupt mailbox semantics in a compact 52-pin STQFP, making it irreplaceable in asymmetric MASTER/SLAVE dual-port topologies requiring hardware-enforced write collision avoidance.
Availability
71421SA35PF is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data loggers, and medical imaging subsystems requiring stable component supply, long-lifecycle support, and guaranteed pin-and-function compatibility with legacy IDT dual-port designs.
Supply support for 71421SA35PF 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, and RF power solutions for communications, computing, and industrial markets.
The IDT71421 product line was engineered specifically for high-reliability, asynchronous dual-ported memory expansion in real-time embedded systems-enabling deterministic interprocessor communication without software arbitration overhead.
FAQ
What is the function of the BUSYR pin on the 71421SA35PF?
The BUSYR pin on the 71421SA35PF is an active-low input used exclusively in SLAVE configuration. When asserted low by the MASTER (IDT71321), it inhibits all write operations to the 71421SA35PF's memory array, preventing data corruption during address contention. It is not an output and has no internal driver-external pull-up is unnecessary unless interfacing with open-drain MASTER outputs.
How does interrupt handling work in the 71421SA35PF?
The 71421SA35PF uses address 7FFH as its right-port interrupt mailbox: a write to this location by the left port asserts the INTR output; a subsequent read or write to 7FFH by the right port clears INTR. This hardware-triggered mechanism eliminates polling and ensures sub-25 ns interrupt latency, as confirmed in the 71421SA35PF datasheet Table 11b.
Can the 71421SA35PF operate as a standalone dual-port RAM without a MASTER device?
Yes-the 71421SA35PF functions as a fully independent dual-port SRAM without requiring a MASTER. Its BUSYR pin is simply held high (VIH) via pull-up if unused, and both ports operate asynchronously. However, BUSY-based arbitration and interrupt mailbox features require connection to IDT71321 or compatible MASTER for full functionality.
What package type and dimensions does the 71421SA35PF use?
The 71421SA35PF is supplied in a 52-pin STQFP (PPG52) package measuring 10 mm × 10 mm × 1.4 mm, with exposed thermal pad and RoHS-compliant lead-free finish. Pinout matches the IDT71321/71421 family layout, enabling PCB reuse across MASTER/SLAVE variants when designed for PPG52 footprint.
Is the 71421SA35PF compatible with industrial temperature range operation?
No-the 71421SA35PF is rated for commercial temperature range only (0°C to +70°C). For industrial operation (–40°C to +85°C), the equivalent part is 71421SA35PI (PLCC) or 71421SA35PG (STQFP), both explicitly qualified per IDT DSC-2691 specification Section 2. The 'F' suffix in 71421SA35PF denotes commercial-grade PPG52 packaging.
71421SA35PF 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 (14x14)
71421SA35PF FAQ
1.How can I place an order for 71421SA35PF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71421SA35PF 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 71421SA35PF reliable?
The price and inventory of 71421SA35PF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71421SA35PF is usually 5 days.
3.What payment methods are accepted for 71421SA35PF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71421SA35PF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71421SA35PF?
71421SA35PF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71421SA35PF 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 71421SA35PF?
For technical support, including 71421SA35PF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71421SA35PF requirements.
6.How does Aetrix verify that 71421SA35PF is sourced from the original manufacturer or authorized distributors?
All 71421SA35PF 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 71421SA35PF meets industry standards.
7.What is the process for return or replacement of 71421SA35PF?
All 71421SA35PF units undergo pre-shipment inspection (PSI). If there is an issue with 71421SA35PF, 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 71421SA35PF part is unused and in its original packaging.
Return procedure for 71421SA35PF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71421SA35PF Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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