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Renesas 71421SA25PF
- Part No.:
- 71421SA25PF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71421SA25PF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,263
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Product details
Overview
71421SA25PF 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, supporting fully asynchronous port-to-port access with BUSY input and interrupt flag (INTR) functionality. It operates at 5 V ±10%, delivers 25 ns max read cycle time, consumes 30 mA typical standby current (TTL-level inputs), and targets industrial temperature range (–40°C to +85°C) for interprocessor communication buffers.
For engineers reviewing the 71421SA25PF datasheet, 71421SA25PF pinout, 71421SA25PF application, or 71421SA25PF equivalent, key selection considerations include its role as a SLAVE dual-port SRAM with BUSY input arbitration, interrupt-driven mailbox protocol (7FFH), 64-pin TQFP package, and compatibility with IDT71321SA MASTER devices in 16-bit+ bus width systems.
Technical Context
The 71421SA25PF implements a dedicated SLAVE architecture: BUSY is an input (not output), enabling write-inhibit control from a companion IDT71321 MASTER; it lacks on-chip arbitration logic and relies entirely on external BUSY assertion for contention resolution. Its interrupt mechanism uses address-mapped flags-writing to 7FFH by the left port sets INTR, and reading 7FFH by the right port clears it.
It supports independent CE-controlled power-down per port, with full standby current as low as 1.0 mA (CMOS-level inputs). Unlike LA variants, the SA suffix denotes standard power operation without battery backup; data retention is not supported. All timing parameters-including tWC = 25 ns, tINS = 25 ns, and tBDD = 35 ns-are specified for industrial-grade operation at VCC = 5.0 V ±10%.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits); provides 16 KB total capacity across two independent ports |
| Access Time (tAA) | 25 ns max; defines minimum address stability window before valid data appears on I/O lines |
| Read Cycle Time (tRC) | 25 ns max; determines maximum sustained read throughput (40 MHz effective rate) |
| Interrupt Set Time (tINS) | 25 ns max; latency from write to 7FFH until INTR flag asserts high |
| BUSY Input Timing (tWB) | 0 ns min; write-to-BUSY propagation delay ensures immediate write inhibition upon BUSY assertion |
| Standby Current (ISB1) | 30 mA typ. (TTL inputs); power draw when both ports are disabled but inputs held at VIH/VIL |
| Supply Voltage | 4.5 V to 5.5 V; single 5 V ±10% rail compatible with legacy TTL/CMOS logic interfaces |
Pinout & Package
71421SA25PF is packaged in a 64-pin TQFP (PNG64) with 0.5 mm pitch, body size 14 mm × 14 mm × 1.4 mm. Pin assignments follow the standard IDT71421 dual-port layout with mirrored left/right port signals and dedicated interrupt/BUSY terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0R–A10R | Right port address inputs | 11-bit address bus selecting one of 2048 locations for right-side access |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit parallel data path; high-impedance when OER = VIH or CER = VIH |
| CER, OER, R/WR | Right port control inputs | Chip enable, output enable, and read/write direction-fully asynchronous with left port |
| INTR | Right port interrupt output | Open-drain flag asserted when left port writes to address 7FFH; requires external pull-up |
| BUSYR | Right port BUSY input | Active-low signal that disables writes when driven low by MASTER device during address contention |
| VCC, GND | Power supply pins | Four VCC and four GND pins distributed for low-noise, stable 5 V operation across high-speed switching |
Key Features
| Feature | Design Value |
|---|---|
| SLAVE-only BUSY interface | Eliminates need for external arbitration logic when paired with IDT71321 MASTER in wide-bus systems |
| Address-mapped interrupt mailbox | Uses fixed SRAM location 7FFH for reliable, hardware-triggered interprocessor signaling without software polling |
| Independent port power control | CE-driven automatic standby reduces dynamic power per active port-critical for multi-processor buffer designs |
| Industrial temperature rating | Guaranteed operation from –40°C to +85°C enables deployment in motor drives, PLCs, and base station equipment |
| 64-pin TQFP footprint | Standardized package supports automated assembly and thermal management in dense embedded layouts |
Applications
| Industrial PLC Memory Buffer | Real-Time Motion Controller |
|---|---|
|
Use Scenario: Dual-CPU architecture where motion CPU writes status updates and PLC CPU reads them via shared memory. IC Role / Device Role / Timing Role: SLAVE dual-port SRAM providing non-blocking, low-latency data exchange between CPUs using BUSY arbitration and INTR handshake. Use Value: Eliminates software semaphores; 25 ns access ensures sub-microsecond response for servo loop coordination. |
Use Scenario: Synchronized axis control requiring deterministic data transfer between FPGA sequencer and ARM host processor. IC Role / Device Role / Timing Role: Hardware mailbox enabling FPGA to signal completion of trajectory calculation via 7FFH write and INTR assertion. Use Value: Reduces interrupt latency to ≤25 ns, guaranteeing timely host response within 100 µs real-time deadlines. |
| Radar Signal Processing Buffer | Avionics Data Concentrator |
|
Use Scenario: High-throughput radar front-end where ADC DMA engine writes raw samples while DSP core reads processed frames. IC Role / Device Role / Timing Role: Asynchronous dual-port memory acting as ping-pong buffer with BUSY-driven flow control preventing overwrites during contention. Use Value: 25 ns tRC sustains >38 MB/s sustained bandwidth; BUSY input prevents data corruption without CPU intervention. |
Use Scenario: Multi-sensor avionics unit aggregating ARINC 429, discrete I/O, and CAN messages into unified telemetry stream. IC Role / Device Role / Timing Role: SLAVE SRAM serving as central message queue, receiving inputs from multiple peripherals via dedicated ports. Use Value: Industrial temp rating and 5 V tolerance ensure reliability in harsh EMI environments; open-drain INTR supports wired-OR fault signaling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C1362BV25 | 3.3 V only; no BUSY input; uses semaphore register instead of address-mapped interrupts | Requires level-shifting for 5 V systems; interrupt handling needs additional register reads | Select when migrating to 3.3 V platforms and software-managed arbitration is acceptable |
| IDT71321SA25PF | MASTER variant with BUSY output, on-chip arbitration, and INTL flag; pin-compatible but functionally asymmetric | Must be used as MASTER in same socket; cannot substitute directly without redesigning BUSY routing and interrupt logic | Choose only when building standalone dual-port or MASTER/SLAVE pair-never as drop-in replacement |
Compared with CY7C1362BV25 and IDT71321SA25PF, the 71421SA25PF uniquely delivers 5 V–compatible SLAVE operation with hardware BUSY input and fixed-address interrupt signaling-enabling simpler, lower-latency interprocessor communication in industrial control and real-time embedded systems.
Availability
71421SA25PF is available at Aetrix Electronics and suitable for industrial PLC memory buffers, real-time motion controllers, and radar signal processing buffers requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for 71421SA25PF 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 and industrial markets.
The IDT71421 product line delivers high-speed dual-port SRAMs optimized for deterministic interprocessor communication in real-time embedded systems-designed specifically to simplify bus-width expansion and eliminate software arbitration overhead.
FAQ
What is the function of the BUSYR pin on the 71421SA25PF?
The BUSYR pin on the 71421SA25PF is an active-low input that disables write operations to the right port when asserted. It receives BUSY signals from a companion IDT71321 MASTER device during address contention, ensuring hardware-enforced write inhibition without CPU involvement. This pin must be driven externally-no internal pull-up or pull-down is provided.
How does interrupt generation work in the 71421SA25PF?
In the 71421SA25PF, the INTR flag is set when the left port writes to memory address 7FFH, and cleared when the right port reads from that same address. This address-mapped mailbox mechanism provides deterministic, low-latency interprocessor signaling with tINS ≤ 25 ns. The INTR output is open-drain and requires an external pull-up resistor.
Can the 71421SA25PF operate as a standalone dual-port RAM without a MASTER device?
Yes, the 71421SA25PF can operate as a standalone dual-port SRAM, but its BUSYR input must be held high (e.g., via pull-up) to enable writes, and interrupt functionality remains usable. However, full BUSY arbitration and MASTER/SLAVE expansion benefits require pairing with an IDT71321 device-the 71421SA25PF lacks internal arbitration logic and BUSY output capability.
What is the maximum operating frequency supported by the 71421SA25PF?
The 71421SA25PF supports a maximum read cycle time (tRC) of 25 ns, corresponding to a theoretical maximum sustained read rate of 40 MHz. Write cycle time (tWC) is also 25 ns. These values are guaranteed over the full industrial temperature range (–40°C to +85°C) and 4.5 V–5.5 V supply, making it suitable for deterministic real-time applications.
Is the 71421SA25PF pin-compatible with other members of the IDT71421 family?
Yes, the 71421SA25PF shares identical 64-pin TQFP (PNG64) pinout with all IDT71421X25 variants-including LA versions and different speed grades (e.g., 71421SA35PF). Differences are limited to internal timing and power characteristics; PCB layout and signal routing remain unchanged across the X25 speed bin.
71421SA25PF 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:
- 25ns
- Access Time:
- 25 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)
71421SA25PF FAQ
1.How can I place an order for 71421SA25PF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71421SA25PF 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 71421SA25PF reliable?
The price and inventory of 71421SA25PF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71421SA25PF is usually 5 days.
3.What payment methods are accepted for 71421SA25PF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71421SA25PF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71421SA25PF?
71421SA25PF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71421SA25PF 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 71421SA25PF?
For technical support, including 71421SA25PF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71421SA25PF requirements.
6.How does Aetrix verify that 71421SA25PF is sourced from the original manufacturer or authorized distributors?
All 71421SA25PF 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 71421SA25PF meets industry standards.
7.What is the process for return or replacement of 71421SA25PF?
All 71421SA25PF units undergo pre-shipment inspection (PSI). If there is an issue with 71421SA25PF, 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 71421SA25PF part is unused and in its original packaging.
Return procedure for 71421SA25PF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71421SA25PF Tags
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M24C02-WMN6TP
STMicroelectronics
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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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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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