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Renesas 71321SA20J
- Part No.:
- 71321SA20J
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
71321SA20J.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,943
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Product details
Overview
IDT71321SA20J 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 systems. It delivers 20 ns max read cycle time, TTL-compatible 5V ±10% operation, and supports independent asynchronous access on left/right ports - used in real-time embedded control, multiprocessor data exchange, and industrial PLC memory buffers.
For engineers reviewing the IDT71321SA20J datasheet, IDT71321SA20J pinout, IDT71321SA20J application, or IDT71321SA20J equivalent, key selection considerations include its master-mode BUSY output behavior, interrupt mailbox addressing (7FEh/7FFh), 52-pin STQFP package compatibility, and industrial-grade timing at –40°C to +85°C.
Technical Context
The IDT71321SA20J implements fully asynchronous dual-port architecture with separate address/control/I/O buses per port, enabling concurrent read/write operations without external synchronization. Its on-chip arbitration logic resolves port contention via BUSY flag generation based on chip enable and address match timing - not R/W state - ensuring deterministic write inhibition during simultaneous access to identical addresses.
As a MASTER device, it features open-drain BUSYL/BUSYR outputs requiring 270 Ω pull-up resistors, two independent interrupt flags (INTL/INTR) tied to dedicated mailbox addresses (7FEh and 7FFh), and automatic power-down controlled by CE pins. It does not support battery backup - that function is exclusive to LA variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 bits (2048 words × 8-bit wide), dual-port SRAM with independent left/right address spaces |
| Access Time (tRC) | 20 ns max - defines minimum read cycle duration; enables 50 MHz sustained throughput per port |
| Supply Voltage | 5.0 V ±10% - TTL-compatible single supply; requires all VCC pins connected to 4.5–5.5 V rail |
| Operating Temperature | –40°C to +85°C - industrial grade; validated across full range for timing and leakage specs |
| Active Current (ICC) | 110 mA typ. - dynamic current with both ports active; determines thermal design and power rail sizing |
| Standby Current (ISB1) | 30 mA typ. - current when both CE pins high; critical for low-power idle states in multi-port systems |
| Interrupt Addressing | INTL asserted on right-port write to 7FEh; INTR asserted on left-port write to 7FFh - enables hardware mailbox signaling |
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; latched on CE or OE transition |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side access; fully independent of left port timing |
| 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; isolated from left port I/O; no internal bus contention |
| CEL / CER | Chip enable (left/right) | Active-low enables respective port; controls power-down mode and memory access |
| OEL / OER | Output enable (left/right) | Active-low enables I/O drivers; allows high-Z state during shared-bus operation |
| R/WL / R/WR | Read/write control (left/right) | Active-low write command; determines direction of data flow on I/O lines |
| INTL / INTR | Interrupt flags (output) | Open-drain outputs; require pull-up; indicate mailbox writes (7FEh/7FFh) |
| BUSYL / BUSYR | BUSY arbitration signals | Open-drain outputs (MASTER only); assert low during port contention; need 270 Ω pull-up |
| VCC / GND | Power supply pins | Multiple VCC/GND pairs - must all be connected to reduce noise and ensure timing integrity |
Key Features
| Feature | Design Value |
|---|---|
| On-chip port arbitration logic | Resolves simultaneous access to same address without external logic; uses CE+address match, not R/W state |
| Dual interrupt mailbox addressing | Hardware-triggered INTL/INTR flags via dedicated SRAM locations (7FEh/7FFh), enabling lock-free IPC |
| Master-only BUSY output capability | BUSYL/BUSYR are open-drain outputs - required for width-expansion with slave devices (e.g., IDT71421) |
| Asynchronous dual-port operation | Fully independent control/address/I/O per port - no clock, no synchronization overhead between processors |
| TTL-compatible 5V interface | Direct connection to legacy microcontrollers and FPGAs without level-shifting; VIH = 2.2 V min, VIL = 0.8 V max |
Applications
| Industrial PLC Memory Buffer | Multiprocessor Real-Time Control |
|---|---|
Use Scenario: Two independent CPUs (e.g., motion controller + safety monitor) share status and command data in deterministic time-critical cycles. IC Role / Device Role / Timing Role: MASTER dual-port SRAM acting as shared memory hub with hardware BUSY arbitration and interrupt signaling. Use Value: Eliminates software polling or semaphores; 20 ns access ensures sub-microsecond inter-processor latency for synchronized I/O updates. |
Use Scenario: Heterogeneous processor pair (ARM + DSP) exchanging sensor fusion results and control commands in autonomous vehicle ECU. IC Role / Device Role / Timing Role: Asynchronous memory bridge with mailbox-based interrupts (7FEh/7FFh) for event-driven data handoff. Use Value: Enables zero-wait-state data transfer between cores; eliminates race conditions via hardware arbitration - no firmware overhead. |
| Avionics Data Logger Interface | Medical Imaging Frame Buffer |
Use Scenario: Flight data recorder captures telemetry from multiple sensors while simultaneously allowing ground-system readout during maintenance. IC Role / Device Role / Timing Role: Dual-port SRAM configured as buffered FIFO with left port for acquisition, right port for host readout. Use Value: Prevents data loss during concurrent capture/read; BUSY flag blocks overwrites during host access - no DMA coherency logic needed. |
Use Scenario: MRI subsystem acquires raw image frames at high rate while display processor renders previews from prior frames. IC Role / Device Role / Timing Role: Shared frame buffer with independent read/write ports; left port for ADC pipeline, right port for GPU fetch. Use Value: Sustains 50+ MB/s bandwidth per port; 20 ns tRC supports >40 MHz pixel clock without wait states or external buffering. |
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-20AXC | 2K × 16 organization; 20 ns access; 5V; no built-in BUSY arbitration - requires external logic for contention resolution | Suitable for wider-data systems but lacks native interrupt/mailbox support and master/slave expansion capability | Select when 16-bit bus width is mandatory and external arbitration is acceptable; avoid if BUSY-driven width expansion is required. |
| IDT71421SA20J | SLAVE counterpart; BUSY pins are inputs (not outputs); no on-chip arbitration logic; identical speed/package | Used only in MASTER/SLAVE configurations - cannot operate standalone as memory hub; relies on IDT71321 for BUSY generation | Choose only as companion to IDT71321SA20J in 16-bit+ systems; never a drop-in replacement - pinout differs in BUSY/INT functionality. |
Compared with CY7C024AV-20AXC, IDT71321SA20J provides integrated arbitration and interrupt mailboxes - reducing BOM count and PCB area. Against IDT71421SA20J, it serves as the sole MASTER with active BUSY output, making it irreplaceable in standalone or primary memory-hub roles.
Availability
IDT71321SA20J is available at Aetrix Electronics and suitable for industrial PLC memory buffers, multiprocessor real-time control systems, avionics data loggers, and medical imaging frame buffers requiring stable component supply and long-term lifecycle assurance.
Supply support for IDT71321SA20J 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, RF, and high-performance computing solutions.
IDT71321SA20J belongs to IDT's legacy dual-port SRAM product line, engineered for deterministic interprocessor communication in mission-critical embedded systems where hardware arbitration and interrupt signaling eliminate software synchronization bottlenecks.
FAQ
What is the operating temperature range for IDT71321SA20J?
IDT71321SA20J is rated for industrial temperature operation from –40°C to +85°C. This range is validated across all AC and DC specifications including access time, standby current, and interrupt timing - no derating required. The SA suffix confirms industrial-grade qualification, distinct from commercial-only variants.
Does IDT71321SA20J support battery backup for data retention?
No, IDT71321SA20J does not support battery backup. Data retention at 2 V is exclusive to LA-suffix variants (e.g., IDT71321LA20J). The SA designation indicates standard active power consumption (325 mW typ.) and no low-voltage retention circuitry - using it with a backup battery will not preserve memory contents.
How does the BUSY arbitration work on IDT71321SA20J?
IDT71321SA20J generates BUSYL/BUSYR as open-drain outputs when both ports attempt access to the same address. Arbitration depends solely on chip enable (CEL/CER) and address match timing - not R/W state. If tAPS (5 ns setup) is violated, BUSY assertion is non-deterministic. Pull-up resistors (270 Ω) are mandatory for proper logic levels.
Can IDT71321SA20J be used as a standalone dual-port RAM without a slave device?
Yes, IDT71321SA20J functions fully as a standalone 2K × 8 dual-port SRAM. Its MASTER capability (BUSY output, arbitration logic, interrupt flags) is optional - all features operate independently. SLAVE pairing (e.g., with IDT71421) is only required for 16-bit+ data bus expansion using shared BUSY signaling.
What are the interrupt mailbox addresses for IDT71321SA20J?
IDT71321SA20J uses fixed SRAM locations for hardware interrupts: writing to address 7FEh (hex) via the right port asserts INTL; writing to 7FFh (hex) via the left port asserts INTR. Clearing is performed by reading those same addresses with OE/CE active - no dedicated control registers or configuration required.
71321SA20J Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 52-LCC (J-Lead)
- Packaging:
- Tube
- 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:
- 52-PLCC (19.13x19.13)
71321SA20J FAQ
1.How can I place an order for 71321SA20J through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321SA20J 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 71321SA20J reliable?
The price and inventory of 71321SA20J are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321SA20J is usually 5 days.
3.What payment methods are accepted for 71321SA20J?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321SA20J transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321SA20J?
71321SA20J orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321SA20J 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 71321SA20J?
For technical support, including 71321SA20J datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321SA20J requirements.
6.How does Aetrix verify that 71321SA20J is sourced from the original manufacturer or authorized distributors?
All 71321SA20J 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 71321SA20J meets industry standards.
7.What is the process for return or replacement of 71321SA20J?
All 71321SA20J units undergo pre-shipment inspection (PSI). If there is an issue with 71321SA20J, 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 71321SA20J part is unused and in its original packaging.
Return procedure for 71321SA20J:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321SA20J 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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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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