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Renesas 71321SA25JI8
- Part No.:
- 71321SA25JI8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
71321SA25JI8.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,793
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Product details
Overview
IDT71321SA25JI8 from Integrated Device Technology (IDT) is a high-speed 2K × 8 dual-port static RAM with on-chip interrupt and BUSY arbitration logic, designed as a MASTER device for interprocessor communication systems. It supports 25 ns max access time, operates at 5V ±10%, delivers 325 mW typical active power, and features open-drain BUSY/INT outputs requiring 270 Ω pull-up resistors. It is used in real-time embedded control systems where two CPUs share memory without software coordination.
For engineers reviewing the IDT71321SA25JI8 datasheet, IDT71321SA25JI8 pinout, IDT71321SA25JI8 application, or IDT71321SA25JI8 equivalent, key selection criteria include its MASTER arbitration capability, 25 ns industrial-grade timing, dual-interrupt mailbox addressing (7FEh/7FFh), and compatibility with SLAVE IDT71421 devices in 16-bit+ bus expansions.
Technical Context
The IDT71321SA25JI8 implements fully asynchronous dual-port operation with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves port contention using chip enable (CE) and address match detection - not R/W state - and asserts open-drain BUSY flags to inhibit writes during conflict.
Interrupt functionality uses dedicated mailbox addresses: writing to 7FEh (right port) sets INTL; reading/writing 7FEh (left port) clears it. Similarly, 7FFh controls INTR. Both interrupts are edge-triggered and latched until explicitly cleared, enabling reliable inter-CPU signaling without polling overhead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16 kB total capacity |
| Access Time (max) | 25 ns - guarantees deterministic read/write latency for real-time CPU co-processing |
| Supply Voltage | 5.0 V ±10% - TTL-compatible single-supply operation, no level-shifting required |
| Active Current (typ) | 110 mA (ICC) - ~325 mW power at 5 V, suitable for thermally constrained embedded designs |
| Standby Current (ISB1) | 30 mA (both ports disabled) - enables low-power idle states between interprocessor transactions |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments including motor drives and PLCs |
| Interrupt Addresses | 7FEh (INTL), 7FFh (INTR) - fixed SRAM locations used as hardware mailboxes for CPU-to-CPU 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 CPU access (0–2047) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side CPU access (0–2047) |
| 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 respective port; controls power-down mode when high |
| OEL / OER | Output enable (left/right) | Active-low enables data output drivers; overrides R/W for tristate control |
| R/WL / R/WR | Read/write control (left/right) | High = read, low = write; determines direction of I/O bus transfer |
| INTL / INTR | Interrupt flags (open-drain) | Asserted low to signal mailbox event; require external 270 Ω pull-up |
| BUSYL / BUSYR | BUSY arbitration signals | BUSYL/BUSYR are outputs on IDT71321SA25JI8; indicate port contention |
| VCC / GND | Power supply pins | Multiple VCC/GND pairs ensure stable noise margin across high-speed operation |
Key Features
| Feature | Design Value |
|---|---|
| On-chip port arbitration logic | Resolves simultaneous access conflicts via CE/address-based priority, eliminating need for external glue logic |
| Dual interrupt mailbox architecture | Hardware-signaled CPU synchronization using dedicated SRAM addresses 7FEh and 7FFh |
| Open-drain BUSY/INT outputs | Enable wired-OR connection in multi-SLAVE systems; 270 Ω pull-up ensures clean TTL-level signaling |
| Asynchronous dual-port operation | Independent left/right timing allows non-synchronized CPU clocks and variable access patterns |
| Master-only BUSY generation | IDT71321SA25JI8 generates BUSY flags; IDT71421 (SLAVE) consumes them - enforces deterministic expansion topology |
Applications
| Industrial PLC Communication Module | Real-Time Motor Control Co-Processor |
|---|---|
Use Scenario: Two microcontrollers exchange motion commands and status feedback in a servo drive system with strict <50 µs response deadlines. IC Role / Device Role / Timing Role: IDT71321SA25JI8 serves as shared memory buffer with hardware arbitration, ensuring atomic updates without software locks or polling. Use Value: 25 ns access time and BUSY-driven write inhibition prevent data corruption during concurrent read/write cycles across CPUs. |
Use Scenario: A safety-critical motion controller uses separate CPUs for trajectory planning and current-loop execution, requiring guaranteed message delivery. IC Role / Device Role / Timing Role: IDT71321SA25JI8 acts as MASTER interrupt-enabled mailbox, triggering hard real-time ISR on command arrival. Use Value: Dedicated 7FEh/7FFh interrupt registers eliminate polling overhead and reduce worst-case latency by >90% vs. software flag checking. |
| Redundant Avionics Data Buffer | Multi-Core DSP Inter-Processor Interface |
Use Scenario: Dual-channel flight control computer shares sensor fusion results while maintaining independence for fault isolation. IC Role / Device Role / Timing Role: IDT71321SA25JI8 provides electrically isolated memory space with hardware-enforced write collision avoidance. Use Value: Industrial temperature range (–40°C to +85°C) and 5V tolerance ensure reliability in unregulated aircraft power environments. |
Use Scenario: Heterogeneous SoC integrates ARM core and DSP core sharing configuration tables and streaming buffers. IC Role / Device Role / Timing Role: IDT71321SA25JI8 functions as bandwidth-optimized inter-core SRAM, supporting burst transfers without bus arbitration delays. Use Value: Asynchronous dual-port design eliminates clock domain crossing logic, simplifying PCB layout and timing closure. |
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 CY7C136-25JC | 2K × 8, 25 ns, but lacks integrated BUSY arbitration and interrupt logic; requires external logic for contention resolution | Suitable only in systems where arbitration is handled in firmware or external CPLD | Select only if interrupt/BUSY features are unused and board space permits added discrete logic |
| IDT71421SA25JI8 | Same speed/package, but SLAVE-only: BUSY pins are inputs, no on-chip arbitration; must be paired with IDT71321 as MASTER | Used exclusively in width-expanded systems (e.g., 16-bit bus) where IDT71321SA25JI8 drives BUSY | Not a drop-in replacement; only valid as companion part in MASTER/SLAVE configurations |
Compared with CY7C136-25JC, IDT71321SA25JI8 reduces BOM count and improves determinism via hardware arbitration; compared with IDT71421SA25JI8, it provides autonomous MASTER control essential for standalone dual-CPU interfaces.
Availability
IDT71321SA25JI8 is available at Aetrix Electronics and suitable for industrial PLCs, real-time motor controllers, and avionics data buffers requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for IDT71321SA25JI8 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 solutions for high-performance computing and industrial systems.
IDT71321SA25JI8 belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in hard real-time embedded systems where software-managed memory sharing introduces unacceptable latency or risk.
FAQ
What is the function of BUSYL and BUSYR on the IDT71321SA25JI8?
BUSYL and BUSYR are open-drain output flags on the IDT71321SA25JI8 that indicate port contention. When both ports attempt simultaneous access to the same memory location, the arbitration logic asserts one BUSY line low to inhibit writes on the losing port. These outputs require external 270 Ω pull-up resistors to VCC and are used to coordinate MASTER/SLAVE configurations - unlike IDT71421, which uses BUSY as an input.
How does interrupt handling work in the IDT71321SA25JI8?
The IDT71321SA25JI8 uses fixed SRAM addresses 7FEh and 7FFh as hardware mailboxes. Writing to 7FEh via the right port sets INTL; reading/writing 7FEh via the left port clears it. Similarly, 7FFh controls INTR. Both flags are latched and remain asserted until explicitly cleared, enabling edge-triggered ISR activation without polling. The IDT71321SA25JI8 implements this entirely in hardware with no firmware dependency.
Can the IDT71321SA25JI8 operate in battery backup mode?
No. Battery backup with 2V data retention is exclusive to LA-suffix variants (e.g., IDT71321LA25JI8). The IDT71321SA25JI8 is the standard-power version and does not support data retention below 4.5 V. Its standby current is 30 mA (ISB1), whereas LA versions achieve 1 mA standby and retain data at 2 V - a key differentiator confirmed in DC Electrical Characteristics Table 4a.
What package type is used for the IDT71321SA25JI8?
The IDT71321SA25JI8 uses a 52-pin STQFP package (package code PPG52), measuring 10 mm × 10 mm × 1.4 mm. This surface-mount, lead-free, RoHS-compliant package is distinct from the 64-pin TQFP variants and is optimized for high-density industrial PCB layouts. Pin configuration matches the PPG52 diagram in Figure 3a of the datasheet (DSC-2691/17).
Is the IDT71321SA25JI8 pin-compatible with IDT71421 devices?
No. Although both share identical pin counts and many signal names, IDT71321SA25JI8 and IDT71421SA25JI8 have opposite BUSY pin roles: BUSYL/BUSYR are outputs on IDT71321SA25JI8 but inputs on IDT71421SA25JI8. Swapping them causes functional failure. They are complementary components - not pin-compatible replacements - intended for MASTER/SLAVE pairing only.
71321SA25JI8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 52-LCC (J-Lead)
- Packaging:
- Tape & Reel (TR)
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 52-PLCC (19.13x19.13)
71321SA25JI8 FAQ
1.How can I place an order for 71321SA25JI8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321SA25JI8 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 71321SA25JI8 reliable?
The price and inventory of 71321SA25JI8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321SA25JI8 is usually 5 days.
3.What payment methods are accepted for 71321SA25JI8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321SA25JI8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321SA25JI8?
71321SA25JI8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321SA25JI8 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 71321SA25JI8?
For technical support, including 71321SA25JI8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321SA25JI8 requirements.
6.How does Aetrix verify that 71321SA25JI8 is sourced from the original manufacturer or authorized distributors?
All 71321SA25JI8 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 71321SA25JI8 meets industry standards.
7.What is the process for return or replacement of 71321SA25JI8?
All 71321SA25JI8 units undergo pre-shipment inspection (PSI). If there is an issue with 71321SA25JI8, 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 71321SA25JI8 part is unused and in its original packaging.
Return procedure for 71321SA25JI8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321SA25JI8 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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