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Renesas 71421SA55PF
- Part No.:
- 71421SA55PF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71421SA55PF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,679
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Product details
Overview
IDT71421SA55PF 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 communication with BUSY input and interrupt flag (INTR) functionality. It delivers 55 ns max read cycle time, operates on single 5V ±10% supply, and features industrial temperature range (–40°C to +85°C) for embedded control and interprocessor data exchange applications.
For engineers reviewing the IDT71421SA55PF datasheet, IDT71421SA55PF pinout, IDT71421SA55PF application, or IDT71421SA55PF equivalent, key selection considerations include its role as SLAVE in width-expanded 16-bit+ memory systems, BUSY input behavior, interrupt mailbox addressing (7FFH), 52-pin STQFP package, and compatibility with IDT71321SA55PF MASTER devices.
Technical Context
The IDT71421SA55PF implements a dedicated SLAVE architecture: BUSY is an input (not output), used to inhibit writes during port contention, and it lacks on-chip arbitration logic - all arbitration decisions are driven externally by the MASTER IDT71321. Its interrupt function uses address 7FFH to set INTR and requires read/write access to that location for flag clearing.
It supports independent asynchronous operation on left (L) and right (R) ports, each with separate CE, OE, R/W, address (A0–A10), and I/O (I/O0–I/O7) signals. Power management is controlled per-port via CE, enabling TTL-compatible standby modes with ISB1 = 20 mA (typ.) at 55 ns speed grade under industrial conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), non-volatile only during active power; no battery backup (SA variant) |
| Max Read Cycle Time (tRC) | 55 ns - defines minimum time between successive reads on same port |
| Supply Voltage | 4.5 V to 5.5 V - single 5V ±10% rail; no dual-supply or low-voltage operation |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments without derating |
| Interrupt Address | 7FFH - write to this location sets INTR; read/write clears it (per Truth Table II) |
| BUSY Function | Input-only - asserted LOW by MASTER to block writes on this SLAVE port during contention |
| Standby Current (ISB1) | 20 mA (typ.) - both ports disabled (CE = VIH), critical for low-power idle states |
Pinout & Package
Package: 52-pin STQFP (PPG52), 10 mm × 10 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 (L/R) | Active-low enables respective port; controls power-down mode when high |
| OEL, OER | Output enable (L/R) | Active-low enables data outputs; does not affect write operations |
| R/WL, R/WR | Read/write control (L/R) | High = read, Low = write; determines direction of I/O pins |
| BUSYR | Busy input (right port) | SLAVE-specific input; LOW inhibits writes on right port during contention |
| BUSYL | Busy input (left port) | SLAVE-specific input; LOW inhibits writes on left port during contention |
| INTR | Interrupt output (right port) | Open-drain flag asserted HIGH when left port writes to 7FFH |
| INTL | Interrupt output (left port) | Open-drain flag asserted HIGH when right port writes to 7FEH |
| VCC | Power supply | Single 5V supply; all VCC pins must be connected to decoupled 5V rail |
| GND | Ground | All GND pins must be connected to common system ground plane |
Key Features
| Feature | Design Value |
|---|---|
| SLAVE-only BUSY interface | Eliminates need for external arbitration logic when paired with IDT71321 MASTER |
| Dual-mailbox interrupt architecture | Enables deterministic interprocessor signaling using dedicated SRAM addresses (7FEH/7FFH) |
| Asynchronous dual-port operation | Allows concurrent, independent read/write access from two processors without clock synchronization |
| 55 ns industrial-grade timing | Guaranteed performance over –40°C to +85°C, enabling use in harsh embedded environments |
| 52-pin STQFP footprint | Compact 10 mm × 10 mm package with exposed pad for thermal management in dense PCB layouts |
Applications
| Industrial PLC Memory Buffer | Avionics Data Exchange Module |
|---|---|
Use Scenario: Two independent microcontrollers share real-time sensor and actuator data in a programmable logic controller chassis. IC Role / Device Role / Timing Role: IDT71421SA55PF acts as SLAVE in a 16-bit-wide dual-port RAM bank, receiving commands from MASTER CPU while feeding status to I/O controller. Use Value: 55 ns access enables sub-100 ns inter-CPU handshaking; BUSY input prevents write collisions during simultaneous access to shared registers. |
Use Scenario: Flight control computer and navigation processor exchange telemetry and command packets via shared memory in DO-254-compliant hardware. IC Role / Device Role / Timing Role: IDT71421SA55PF serves as SLAVE in a fault-tolerant dual-ported memory subsystem, with INTR signaling used for packet-ready notification. Use Value: Industrial temperature rating ensures reliability across cabin and avionics bay thermal profiles; open-drain INTR allows wired-OR interrupt aggregation. |
| Medical Imaging Frame Buffer | Test Equipment Pattern Generator |
Use Scenario: MRI subsystem uses dual CPUs - one for image acquisition, another for real-time reconstruction - sharing raw k-space data. IC Role / Device Role / Timing Role: IDT71421SA55PF operates as SLAVE in a width-expanded memory array, synchronized to MASTER timing for burst transfers. Use Value: Asynchronous operation eliminates clock domain crossing; 52-pin STQFP enables high-density layout alongside ADC/DAC FPGAs. |
Use Scenario: Automated test equipment streams stimulus patterns from host PC to pattern generator FPGA, with results returned via shared memory. IC Role / Device Role / Timing Role: IDT71421SA55PF functions as SLAVE in a 32-bit memory interface, where MASTER handles PCIe-to-memory bridging. Use Value: 55 ns tRC supports >18 MHz sustained data throughput; BUSY input guarantees atomic write completion during high-speed vector loading. |
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-55AXC | 55 ns, 2K × 16 organization; single-port compatible but no native SLAVE BUSY input | Requires external logic for MASTER/SLAVE arbitration; wider data bus reduces chip count but increases complexity | Choose when 16-bit native width is preferred and external arbitration is acceptable |
| ON Semiconductor NVSRAM-NV71321SA55PF | Same pinout and timing, but adds nonvolatile storage via integrated EEPROM backup | Supports data retention after power loss; higher cost and write-cycle endurance limits apply | Choose when power-fail data preservation is required beyond standard SRAM operation |
Compared with IDT71421SA55PF, CY7C024AV-55AXC offers native 16-bit width but lacks SLAVE-specific BUSY input, increasing design complexity for width expansion; NV71321SA55PF adds nonvolatility at the cost of write endurance and price premium - neither is pin-compatible, but both serve overlapping interprocessor memory roles.
Availability
IDT71421SA55PF is available at Aetrix Electronics and suitable for industrial PLC memory buffers, avionics data exchange modules, and medical imaging frame buffers requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for IDT71421SA55PF 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, designs high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.
The IDT71421SA55PF belongs to IDT's dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time embedded systems where hardware arbitration and interrupt signaling are critical.
FAQ
What is the function of BUSY pins on the IDT71421SA55PF?
The BUSYL and BUSYR pins on the IDT71421SA55PF are inputs - not outputs - and serve as write-inhibit signals from an external MASTER device (e.g., IDT71321SA55PF). When either BUSY pin is driven LOW, the corresponding port (left or right) blocks write operations regardless of R/W or CE state, ensuring data coherency during address contention. This SLAVE-specific behavior eliminates need for discrete arbitration logic.
How does interrupt handling work in the IDT71421SA55PF?
The IDT71421SA55PF uses address 7FFH as its interrupt mailbox: a write to this location by the opposite port asserts the INTR (or INTL) flag. To clear the flag, the local port must perform a read or write access to 7FFH. The flag is open-drain and requires an external pull-up resistor. This mechanism enables lock-free, hardware-synchronized messaging without software polling overhead in the IDT71421SA55PF.
Is the IDT71421SA55PF pin-compatible with the IDT71321SA55PF?
No - the IDT71421SA55PF and IDT71321SA55PF share identical pinouts in the 52-pin STQFP package, but their BUSY pin functions differ fundamentally: BUSY is an output on IDT71321SA55PF (MASTER) and an input on IDT71421SA55PF (SLAVE). Swapping them without redesigning BUSY signal routing will cause functional failure. They are functionally complementary, not drop-in replacements.
Does the IDT71421SA55PF support battery backup or data retention below 5V?
No - the IDT71421SA55PF is the SA (standard power) variant and does not support battery backup or low-voltage data retention. Only LA variants (e.g., IDT71421LA55PF) guarantee data retention at 2.0 V. The IDT71421SA55PF requires continuous 4.5–5.5 V supply for reliable operation; voltage dropout below 4.5 V may result in data corruption or loss.
What are the power consumption characteristics of the IDT71421SA55PF at 55 ns speed?
At 55 ns speed grade and industrial temperature, the IDT71421SA55PF draws 65 mA (typ.) dynamic current (ICC) with both ports active, 20 mA (typ.) standby current (ISB1) when both ports are disabled, and 40 mA (typ.) when one port is active (ISB2). These values assume VCC = 5.0 V and are measured per DC Electrical Characteristics Table 4b in the official datasheet for the IDT71421SA55PF.
71421SA55PF 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:
- 55ns
- Access Time:
- 55 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)
71421SA55PF FAQ
1.How can I place an order for 71421SA55PF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71421SA55PF 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 71421SA55PF reliable?
The price and inventory of 71421SA55PF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71421SA55PF is usually 5 days.
3.What payment methods are accepted for 71421SA55PF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71421SA55PF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71421SA55PF?
71421SA55PF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71421SA55PF 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 71421SA55PF?
For technical support, including 71421SA55PF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71421SA55PF requirements.
6.How does Aetrix verify that 71421SA55PF is sourced from the original manufacturer or authorized distributors?
All 71421SA55PF 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 71421SA55PF meets industry standards.
7.What is the process for return or replacement of 71421SA55PF?
All 71421SA55PF units undergo pre-shipment inspection (PSI). If there is an issue with 71421SA55PF, 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 71421SA55PF part is unused and in its original packaging.
Return procedure for 71421SA55PF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71421SA55PF Tags
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