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Renesas 71321SA55JG
- Part No.:
- 71321SA55JG
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
71321SA55JG.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,425
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Product details
Overview
71321SA55JG from IDT (now Renesas) is a high-speed 2K × 8 dual-port static RAM with interrupt and BUSY arbitration logic, designed as the MASTER device in master/slave memory expansion systems. It supports 55 ns max access time, operates on single 5V ±10% supply, features open-drain BUSY/INT outputs requiring 270Ω pull-ups, and delivers 200 µW typical standby power in LA variants - used in real-time interprocessor communication buffers for industrial motion controllers.
For engineers reviewing the 71321SA55JG datasheet, 71321SA55JG pinout, 71321SA55JG application, or 71321SA55JG equivalent, key selection criteria include its 55 ns read cycle time (tRC), dual independent asynchronous ports, on-chip arbitration logic, interrupt mailbox addressing (7FEh/7FFh), and 52-pin STQFP package compatibility with industrial temperature range (–40°C to +85°C).
Technical Context
The 71321SA55JG implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port - enabling concurrent read/write operations without internal synchronization overhead. Its BUSY arbitration logic responds solely to chip enable (CEL/CER) and address match timing (tAPS = 5 ns), independent of R/W state, and asserts open-drain BUSYL/BUSYR outputs to inhibit conflicting writes.
Interrupt functionality uses dedicated SRAM addresses (7FEh for INTL, 7FFh for INTR) as mailbox registers: a write to 7FEh by the right port sets INTL; a read from 7FEh by the left port clears it. The device supports battery backup data retention down to 2V only in LA variants - not applicable to this SA-grade part.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2K × 8 bits (2048 words × 8-bit wide), providing 16 KB addressable space per port |
| Access Time (tAA) | 55 ns max - defines worst-case delay from valid address to stable output data |
| Read Cycle Time (tRC) | 55 ns max - minimum interval between successive read cycles on same port |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible single 5V ±10% rail, no auxiliary supplies required |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments without derating |
| Standby Current (ISB1) | 20 mA max (typ. 20 mA) - power consumed when both ports disabled (CE = VIH) |
| Output Type | Open-drain BUSY/INT pins - require external 270Ω pull-up resistors for proper logic level assertion |
Pinout & Package
71321SA55JG is packaged in 52-pin STQFP (PPG52), measuring 10 mm × 10 mm × 1.4 mm, with exposed thermal pad 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 memory access (0–2047 decimal) |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit data path; direction controlled by R/WL and OEL |
| CEL, OEL, R/WL | Left port controls | Chip enable, output enable, and read/write select - fully independent of right port |
| BUSYL, INTL | Left port open-drain flags | BUSYL indicates left-port write contention; INTL signals right-port mailbox write (7FEh) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit data path; direction controlled by R/WR and OER |
| CER, OER, R/WR | Right port controls | Independent enable and direction control - enables true concurrent operation |
| BUSYR, INTR | Right port open-drain flags | BUSYR indicates right-port write contention; INTR signals left-port mailbox write (7FFh) |
| VCC, GND | Power terminals | Multiple VCC/GND pins distributed across package for low-noise, low-impedance supply routing |
Key Features
| Feature | Design Value |
|---|---|
| On-chip arbitration logic | Eliminates need for external glue logic in master/slave configurations - BUSY assertion based on CE/address timing only |
| Dual independent interrupt mailboxes | Hardware-accelerated interprocessor signaling via dedicated SRAM addresses (7FEh/7FFh), reducing software polling overhead |
| Asynchronous dual-port operation | Enables simultaneous read/write to different memory locations - critical for real-time buffer handoff between CPUs |
| 55 ns industrial-grade timing | Guaranteed performance at –40°C to +85°C without speed binning or voltage margining |
| Low-power standby mode | 20 mA max ISB1 current allows rapid wake-up from power-down without initialization latency |
Applications
| Industrial Motion Controller Buffer | Redundant PLC Communication Interface |
|---|---|
Use Scenario: Two independent microcontrollers exchange position setpoints and status updates in a closed-loop servo drive system. IC Role / Device Role / Timing Role: 71321SA55JG acts as MASTER dual-port RAM, synchronizing data transfer via BUSY arbitration and INTL/INTR flags to prevent race conditions. Use Value: Eliminates software semaphores and reduces inter-CPU latency to ≤55 ns, enabling deterministic 10 kHz motion loop execution. |
Use Scenario: Primary and backup PLCs maintain mirrored I/O states using shared memory for failover coordination. IC Role / Device Role / Timing Role: 71321SA55JG serves as non-volatile shared register bank; one port connects to primary CPU, the other to backup CPU. Use Value: Hardware BUSY logic prevents simultaneous writes during switchover, ensuring atomic state updates without firmware intervention. |
| Avionics Data Acquisition Hub | Medical Imaging Real-Time FIFO |
Use Scenario: Sensor acquisition processor streams ADC samples into memory while flight management unit reads processed frames. IC Role / Device Role / Timing Role: 71321SA55JG provides asynchronous dual-port buffer with interrupt-driven frame ready signaling (7FFh mailbox). Use Value: Guarantees zero-data-loss streaming at 20 MSPS by decoupling acquisition and processing clocks via hardware arbitration. |
Use Scenario: MRI subsystem transfers raw k-space data from FPGA to DSP core with minimal pipeline stall. IC Role / Device Role / Timing Role: 71321SA55JG functions as ping-pong buffer - FPGA writes to one port while DSP reads from the other. Use Value: 55 ns tRC enables sustained 18 MB/s throughput, matching FPGA DDR2 interface bandwidth without wait states. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C024AV-55AXC | 55 ns access, 2K × 16 organization, 3.3V supply, no built-in BUSY arbitration | Requires external logic for port conflict resolution; suited for wider data paths but higher voltage margining needed | Select when 16-bit word width is mandatory and external arbitration is acceptable |
| IDT71421SA55JG | SLAVE-only variant; BUSY pins are inputs (not outputs); identical timing and pinout except BUSY/INT function reversal | Must be paired with 71321SA55JG in master/slave configuration; cannot operate standalone as MASTER | Use only as companion SLAVE in 16-bit+ expansions - never as direct replacement for 71321SA55JG |
Compared with CY7C024AV-55AXC and IDT71421SA55JG, the 71321SA55JG uniquely integrates MASTER arbitration logic and interrupt mailboxes in a 5V/55 ns industrial package - enabling self-contained dual-CPU communication without external logic or voltage translation.
Availability
71321SA55JG is available at Aetrix Electronics and suitable for industrial motion control, redundant PLC interfaces, avionics data acquisition, and medical imaging systems requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for 71321SA55JG 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
IDT (Integrated Device Technology), now part of Renesas Electronics, specializes in high-performance memory, timing, and interface solutions for industrial, communications, and computing markets.
The 71321SA55JG belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time embedded systems where hardware arbitration and interrupt signaling eliminate software bottlenecks.
FAQ
What is the maximum operating temperature range for the 71321SA55JG?
The 71321SA55JG is rated for industrial temperature operation from –40°C to +85°C, with all AC and DC specifications guaranteed across this full range - no derating required for timing or power consumption at temperature extremes.
Does the 71321SA55JG support battery backup data retention?
No - battery backup data retention (2V operation) is exclusive to LA-grade variants like 71321LA55JG. The 71321SA55JG is an SA-grade part and requires continuous 4.5–5.5 V supply for reliable operation and data retention.
How does BUSY arbitration work on the 71321SA55JG?
The 71321SA55JG asserts BUSYL or BUSYR when both ports attempt simultaneous access to the same address. Arbitration is based solely on CE and address timing (tAPS = 5 ns), not R/W state - the port with earlier stable CE/address wins, and the losing port's write is internally inhibited.
Can the 71321SA55JG be used as a standalone dual-port RAM without a slave device?
Yes - the 71321SA55JG functions as a complete standalone 2K × 8 dual-port SRAM. Its MASTER designation refers to capability, not requirement; the SLAVE (71421) is optional and only needed for 16-bit or wider data bus expansion.
What pull-up resistor value is required for BUSY and INT pins on the 71321SA55JG?
IDT specifies a 270Ω pull-up resistor to VCC for all open-drain BUSY and INT outputs (BUSYL, BUSYR, INTL, INTR) on the 71321SA55JG - required to meet VOL ≤ 0.5 V at IOL = 16 mA per the datasheet.
71321SA55JG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 52-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Active
- 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:
- 52-PLCC (19.13x19.13)
71321SA55JG FAQ
1.How can I place an order for 71321SA55JG through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321SA55JG 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 71321SA55JG reliable?
The price and inventory of 71321SA55JG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321SA55JG is usually 5 days.
3.What payment methods are accepted for 71321SA55JG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321SA55JG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321SA55JG?
71321SA55JG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321SA55JG 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 71321SA55JG?
For technical support, including 71321SA55JG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321SA55JG requirements.
6.How does Aetrix verify that 71321SA55JG is sourced from the original manufacturer or authorized distributors?
All 71321SA55JG 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 71321SA55JG meets industry standards.
7.What is the process for return or replacement of 71321SA55JG?
All 71321SA55JG units undergo pre-shipment inspection (PSI). If there is an issue with 71321SA55JG, 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 71321SA55JG part is unused and in its original packaging.
Return procedure for 71321SA55JG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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