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Renesas 71421SA20PF
- Part No.:
- 71421SA20PF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71421SA20PF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,657
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Product details
Overview
IDT71421SA20PF from Integrated Device Technology is a 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) for interprocessor signaling. It delivers 20 ns read cycle time, operates on single 5V ±10% supply, and targets industrial embedded control applications requiring deterministic arbitration between two processors sharing memory.
For engineers reviewing the IDT71421SA20PF datasheet, IDT71421SA20PF pinout, IDT71421SA20PF application, or IDT71421SA20PF equivalent, key selection criteria include its role as SLAVE in width-expanded memory systems, BUSY input behavior, interrupt mailbox addressing (7FFH), 52-pin STQFP package, and compatibility with IDT71321SA20PF MASTER devices.
Technical Context
The IDT71421SA20PF implements a dedicated SLAVE architecture: BUSY is an input (not output), enabling write-inhibit functionality when asserted by a MASTER device; it lacks on-chip arbitration logic, relying entirely on external BUSY signal coordination. Its interrupt generation is triggered solely by writes to address 7FFH from the opposite port, with INTR cleared only upon read access to that same location.
It supports independent left/right port operation with separate CE, OE, R/W, and address buses; all control signals are TTL-compatible; power-down is controlled per-port via CE, achieving 30 mA typical standby current (TTL-level inputs) and 1.0 mA full standby (CMOS-level inputs) at 25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16 KB total capacity |
| Access Time (tAA) | 20 ns max - defines minimum address hold before valid data appears |
| Read Cycle Time (tRC) | 20 ns max - sets minimum interval between successive reads |
| Write Pulse Width (tWP) | 15 ns min - shortest R/W-controlled write enable duration ensuring reliable write |
| Standby Current (ISB1) | 30 mA typ. - power draw when both ports disabled with TTL-level CE high |
| Supply Voltage | 4.5–5.5 V - single 5V ±10% rail, no auxiliary supplies required |
| Operating Temperature | 0°C to +70°C - commercial grade, not rated for industrial −40°C to +85°C |
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 (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; controls per-port power-down mode |
| OEL / OER | Output enable (left/right) | Active-low enables data outputs; high-Z when deasserted |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines I/O direction and internal timing |
| BUSYL / BUSYR | BUSY input (SLAVE) | Inputs only - assert low to inhibit writes on respective port; require external MASTER drive |
| INTL / INTR | Interrupt flags (open-drain) | INTL set by right-port write to 7FEH; INTR set by left-port write to 7FFH |
| VCC / GND | Power and ground | All VCC pins must be connected to 5V; all GND pins to system ground |
Key Features
| Feature | Design Value |
|---|---|
| SLAVE-only BUSY interface | Eliminates need for external arbitration logic when paired with IDT71321 MASTER |
| Dual-mailbox interrupt architecture | Hardware-automated interprocessor signaling using dedicated SRAM addresses (7FEH/7FFH) |
| Asynchronous dual-port operation | Independent left/right access with no shared clocks or synchronization overhead |
| Per-port power management | CE-driven standby reduces active current to 30 mA (typ.) or full standby to 1.0 mA (typ.) |
| TTL-compatible signaling | Direct interface with 5V microcontrollers and FPGAs without level-shifting |
Applications
| Real-Time Industrial PLC | Multi-Core DSP Memory Sharing |
|---|---|
Use Scenario: Two independent CPU cores (e.g., ARM Cortex-M4 + RISC-V) share sensor data and control commands in a programmable logic controller. IC Role / Device Role / Timing Role: IDT71421SA20PF acts as SLAVE memory buffer, receiving BUSY from MASTER to prevent concurrent writes during critical state updates. Use Value: Ensures deterministic memory coherency without software locks, leveraging hardware BUSY arbitration to avoid race conditions on shared I/O registers. |
Use Scenario: A dual-DSP system (e.g., TI C6000 + Analog Devices SHARC) exchanges audio processing buffers and configuration parameters. IC Role / Device Role / Timing Role: IDT71421SA20PF provides interrupt-driven mailbox communication: one DSP writes to 7FFH, triggering INTR to notify the other DSP of new data. Use Value: Reduces inter-processor latency to ≤25 ns interrupt set time, enabling sub-microsecond message passing without polling overhead. |
| Avionics Data Acquisition Unit | Medical Imaging Control Subsystem |
Use Scenario: Flight control computer and health monitoring unit exchange telemetry and fault logs in DO-254-certified avionics hardware. IC Role / Device Role / Timing Role: IDT71421SA20PF serves as SLAVE in a redundant 16-bit memory bank, synchronized via IDT71321 MASTER's BUSY output. Use Value: Guarantees atomic 16-bit word writes across ports with 20 ns access, meeting deterministic timing requirements for safety-critical data handoff. |
Use Scenario: MRI subsystem uses two processors: one handles real-time gradient waveform generation, the other manages image reconstruction. IC Role / Device Role / Timing Role: IDT71421SA20PF stores calibration tables and acquisition parameters, accessed concurrently with hardware-enforced BUSY arbitration. Use Value: Prevents corruption of time-sensitive calibration data during simultaneous read/write, using tBDD ≤25 ns to ensure valid data after BUSY deassertion. |
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 CY7C1371DV33-200BZI | 3.3V supply, 200 MHz QDR interface, no native BUSY arbitration logic | Requires external logic for MASTER/SLAVE contention resolution; suited for high-speed cache, not deterministic IPC | Select if migrating to 3.3V systems and implementing custom arbitration in FPGA |
| ISSI IS61WV20488BLL-20MLI | Single-port, 2K × 8, 20 ns access, no interrupts or BUSY; 3.3V/5V tolerant | Lacks dual-port concurrency and interprocessor signaling - requires software-managed semaphores | Choose only for cost-sensitive designs where true concurrency is unnecessary |
Compared with CY7C1371DV33-200BZI and IS61WV20488BLL-20MLI, the IDT71421SA20PF uniquely integrates hardware BUSY input and interrupt mailbox logic in a 5V SLAVE configuration, eliminating external arbitration components and reducing interprocessor latency to under 25 ns - critical for hard real-time embedded control.
Availability
IDT71421SA20PF is available at Aetrix Electronics and suitable for real-time industrial PLCs, multi-core DSP memory sharing, avionics data acquisition units, and medical imaging control subsystems requiring stable component supply and long-term production continuity.
Supply support for IDT71421SA20PF 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 IDT71421SA20PF belongs to IDT's legacy dual-port SRAM product line, designed specifically for deterministic interprocessor communication in embedded control systems using MASTER/SLAVE memory expansion topologies.
FAQ
What is the function of BUSY pins on the IDT71421SA20PF?
The BUSYL and BUSYR pins on the IDT71421SA20PF are inputs-not outputs-because this device operates exclusively as a SLAVE in MASTER/SLAVE configurations. When driven low by an external IDT71321 MASTER device, they inhibit writes on the respective port. The IDT71421SA20PF does not generate BUSY signals internally; it relies entirely on external arbitration. Pull-up resistors are not required on these pins since they are inputs.
How does interrupt handling work in the IDT71421SA20PF?
The IDT71421SA20PF asserts its INTR flag when the left port writes to address 7FFH, and clears INTR only upon a read access to that same address. Similarly, INTL is set by right-port writes to 7FEH. These are open-drain outputs requiring external pull-ups. The IDT71421SA20PF does not support auto-clear or edge-triggered interrupts-clearing is strictly level-sensitive and requires explicit read access to the mailbox address.
Can the IDT71421SA20PF be used as a standalone dual-port RAM without a MASTER device?
No. The IDT71421SA20PF lacks on-chip arbitration logic and BUSY output capability. Using it without an IDT71321 MASTER risks simultaneous write collisions and data corruption. Its BUSY pins are inputs only, and its interrupt flags depend on cross-port writes-both functions assume coordinated MASTER/SLAVE operation. Standalone use violates the device's architectural intent and is unsupported per datasheet functional description.
What package and pin count does the IDT71421SA20PF use?
The IDT71421SA20PF is packaged in a 52-pin STQFP (PPG52) with 10 mm × 10 mm footprint and 1.4 mm height. It is not offered in PLCC, TQFP, or STQFP-64 variants. Pin compatibility with IDT71321SA20PF is maintained in this package, enabling direct PCB layout reuse in MASTER/SLAVE pairs. Lead-free and RoHS-compliant construction is standard.
Does the IDT71421SA20PF support battery backup or low-voltage retention?
No. The IDT71421SA20PF is the SA (standard power) variant and does not support battery backup operation. Only LA (low-power) versions like IDT71421LA20PF provide 2V data retention capability. The SA version draws 110 mA typical dynamic current and has no specification for operation below 4.5 V; retention functionality is absent from its DC electrical characteristics table and functional description.
71421SA20PF 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:
- 20ns
- Access Time:
- 20 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)
71421SA20PF FAQ
1.How can I place an order for 71421SA20PF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71421SA20PF 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 71421SA20PF reliable?
The price and inventory of 71421SA20PF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71421SA20PF is usually 5 days.
3.What payment methods are accepted for 71421SA20PF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71421SA20PF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71421SA20PF?
71421SA20PF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71421SA20PF 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 71421SA20PF?
For technical support, including 71421SA20PF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71421SA20PF requirements.
6.How does Aetrix verify that 71421SA20PF is sourced from the original manufacturer or authorized distributors?
All 71421SA20PF 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 71421SA20PF meets industry standards.
7.What is the process for return or replacement of 71421SA20PF?
All 71421SA20PF units undergo pre-shipment inspection (PSI). If there is an issue with 71421SA20PF, 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 71421SA20PF part is unused and in its original packaging.
Return procedure for 71421SA20PF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71421SA20PF Tags
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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