My Inquiry
My Account
Renesas 71321SA55PFI
- Part No.:
- 71321SA55PFI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321SA55PFI.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,070
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
71321SA55PFI from IDT (now Renesas) is a high-speed 2K × 8 dual-port static RAM with interrupt and BUSY arbitration logic, designed as a MASTER device for interprocessor communication in real-time embedded systems. It features 55 ns max access time, TTL-compatible 5V ±10% operation, industrial temperature range (–40°C to +85°C), and dual independent asynchronous ports enabling concurrent read/write access to shared memory - used in motor control co-processor interfaces and digital signal processor (DSP) offload buffers.
For engineers reviewing the 71321SA55PFI datasheet, 71321SA55PFI pinout, 71321SA55PFI application, or 71321SA55PFI equivalent, this page delivers verified technical context, exact pin roles per port, confirmed interrupt timing (tINS = 45 ns max), BUSY arbitration behavior, and validated alternatives for master-side dual-port SRAM replacement in deterministic real-time systems.
Technical Context
The 71321SA55PFI implements on-chip port arbitration logic that asserts BUSYL/BUSYR outputs when address contention occurs between left and right ports - based solely on chip enable (CEL/CER) and address match timing (tAPS = 5 ns min), independent of R/W state. Its interrupt subsystem uses dedicated mailbox addresses (7FEH for INTL, 7FFH for INTR) with set/reset timing tINS/tINR ≤ 45 ns (max) at 55 ns speed grade.
It supports two distinct power modes: active operation (ICC ≤ 65 mA typ. at 55 ns) and full standby (ISB3 ≤ 1.0 mA typ.) via CMOS-level CE control. The BUSY outputs are open-drain and require external 270 Ω pull-up resistors; all VCC and GND pins must be connected per package layout rules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2K × 8 bits (2048 words × 8-bit data width), providing shared buffer space for two independent processors or cores. |
| Access Time | 55 ns (max), defining worst-case latency from address/CE assertion to valid data output - critical for real-time synchronization. |
| Operating Voltage | 5.0 V ±10%, compatible with legacy TTL and 5V microcontroller buses without level translation. |
| Temperature Range | –40°C to +85°C (industrial grade), qualified for use in motor drives, industrial PLCs, and outdoor communications equipment. |
| Interrupt Timing | tINS/tINR ≤ 45 ns (max), ensuring fast mailbox flag assertion/clearing for low-latency inter-processor signaling. |
| BUSY Arbitration | tBAA/tBAC ≤ 30 ns (max), guaranteeing rapid detection and inhibition of conflicting writes to same address across ports. |
| Power Consumption | Active: 65 mA typ.; Full Standby: 1.0 mA typ., enabling energy-efficient operation during idle cycles in battery-backed systems. |
Pinout & Package
71321SA55PFI is packaged in a 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 access; A10L enables full 2K address space (000–7FFH). |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit data path; high-impedance when OEL = VIH or CEL = VIH - supports bus sharing. |
| CEL, OEL, R/WL | Left port controls | Chip Enable (active-low), Output Enable (active-low), Read/Write (active-low); fully asynchronous operation. |
| INTL, BUSYL | Left port interrupt & BUSY | INTL is push-pull interrupt flag; BUSYL is open-drain BUSY output requiring 270 Ω pull-up - signals left-port write contention. |
| A0R–A10R | Right port address inputs | Independent 11-bit address bus; matches left port for arbitration - no internal address translation. |
| I/O0R–I/O7R | Right port bidirectional data | Electrically isolated 8-bit path; timing and drive strength identical to left port for symmetrical system design. |
| CER, OER, R/WR | Right port controls | Functionally identical to left-side controls; enables true dual-port concurrency without arbitration overhead. |
| INTR, BUSYR | Right port interrupt & BUSY | INTR is push-pull; BUSYR is open-drain - provides mirrored status signaling for right-port activity and conflict detection. |
| VCC, GND | Power supply | Multiple VCC/GND pins distributed across package - mandatory connection required for stable operation and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| On-chip arbitration logic | Eliminates need for external glue logic in MASTER/SLAVE configurations - reduces PCB area and routing complexity in 16-bit+ memory expansions. |
| Dual independent interrupt mailboxes | Hardware-accelerated interprocessor signaling using fixed addresses 7FEH/7FFH, enabling deterministic response without polling or software overhead. |
| Open-drain BUSY outputs | Enables wired-OR expansion across multiple MASTER devices - supports scalable multi-SRAM arrays with unified BUSY indication. |
| Asynchronous dual-port operation | Permits simultaneous, unsynchronized access from two clock domains - essential for heterogeneous processor integration (e.g., ARM + DSP). |
| Industrial-grade reliability | Qualified over –40°C to +85°C with 100% production-tested AC timing - ensures consistent performance in harsh environments. |
Applications
| Motor Control Co-Processor Interface | DSP Offload Buffer |
|---|---|
Use Scenario: Real-time servo loop running on FPGA reads position feedback while MCU writes updated PWM parameters into shared RAM. IC Role / Device Role / Timing Role: 71321SA55PFI acts as MASTER dual-port SRAM, synchronizing FPGA and MCU via BUSY arbitration and INTL/INTR flags. Use Value: 55 ns access and sub-50 ns interrupt timing eliminate polling delays, enabling 20 kHz closed-loop update rates without jitter. | Use Scenario: Audio DSP performs FFT processing while host ARM processor streams new sample blocks and retrieves results. IC Role / Device Role / Timing Role: 71321SA55PFI serves as zero-wait-state shared buffer; left port connects to DSP, right port to ARM AXI bus interface. Use Value: Asynchronous dual-port architecture avoids bus contention, sustaining 80 MB/s aggregate throughput across both ports. |
| Redundant Safety Controller Memory | Industrial PLC I/O Mapping Table |
Use Scenario: Dual-core lockstep safety controller validates memory writes via cross-checking - one core writes, other verifies. IC Role / Device Role / Timing Role: 71321SA55PFI provides atomic, hardware-arbitrated memory access; BUSY prevents simultaneous writes to same location. Use Value: Deterministic tBDD ≤ 50 ns ensures immediate write inhibition during contention - meeting SIL-3 functional safety timing requirements. | Use Scenario: PLC main CPU updates I/O configuration tables while real-time I/O scan engine reads current state values. IC Role / Device Role / Timing Role: 71321SA55PFI functions as MASTER SRAM bridging CPU and scan engine; INTL/INTR flags signal table update completion. Use Value: 5V TTL compatibility integrates directly with legacy 5V I/O ASICs; industrial temp rating supports operation inside DIN-rail enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C1371BV33-133AXC | 3.3V core, 133 MHz QDR interface, no native BUSY arbitration - requires external logic for contention resolution. | Targeted at high-bandwidth networking ASICs; lacks interrupt mailboxes and 5V compatibility. | Select only if migrating to 3.3V domain and adding custom arbitration; not drop-in for 71321SA55PFI's MASTER role. |
| IDT71421SA55PF | SLAVE-only variant; BUSY pins are inputs (not outputs); no on-chip arbitration logic; identical timing and pinout except BUSY/INT function reversal. | Used only in width-expanded arrays paired with 71321SA55PFI; cannot operate standalone as MASTER. | Valid companion part for 16-bit+ systems but not functionally equivalent - never substitutes for 71321SA55PFI in MASTER configuration. |
Compared with CY7C1371BV33-133AXC and IDT71421SA55PF, the 71321SA55PFI uniquely combines 5V operation, integrated MASTER arbitration, open-drain BUSY outputs, and hardware interrupt mailboxes - making it irreplaceable in legacy industrial designs requiring deterministic, self-contained dual-port memory control.
Availability
71321SA55PFI is available at Aetrix Electronics and suitable for motor control co-processors, DSP offload buffers, redundant safety controllers, and industrial PLC I/O mapping requiring stable component supply across extended product lifecycles.
Supply support for 71321SA55PFI 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, is a fabless semiconductor company specializing in high-performance memory, timing, and interface solutions for communications, computing, and industrial markets.
The 71321SA55PFI belongs to IDT's dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time embedded systems where hardware arbitration and low-latency interrupts are mandatory.
FAQ
What is the maximum operating temperature range for the 71321SA55PFI?
The 71321SA55PFI is rated for industrial temperature operation from –40°C to +85°C. This specification is guaranteed across all electrical parameters including tRC = 55 ns (max), tINS/tINR ≤ 45 ns, and ISB3 ≤ 1.0 mA - validated per IDT DSC-2691/17 datasheet revision September 2019.
Does the 71321SA55PFI support battery backup data retention?
No, the 71321SA55PFI does not support battery backup data retention. That feature is exclusive to LA-suffix variants (e.g., 71321LA55PFI), which specify VDR = 2.0 V and ICCDR ≤ 4000 µA at –40°C to +85°C. The SA suffix indicates standard active-power operation only.
How are the BUSY outputs configured on the 71321SA55PFI?
The 71321SA55PFI features open-drain BUSYL and BUSYR outputs requiring external 270 Ω pull-up resistors to VCC. These signals assert low during address contention to inhibit writes on the respective port - a core part of its MASTER arbitration function, as defined in Truth Table III and Timing Waveform drw 12–13.
Can the 71321SA55PFI be used as a SLAVE device in a dual-port array?
No, the 71321SA55PFI is exclusively a MASTER device. Its BUSY pins are outputs and include on-chip arbitration logic. SLAVE functionality is implemented only in the IDT71421 series (e.g., 71421SA55PF), where BUSY pins are inputs and arbitration is disabled - per Functional Description section and Pin Configurations note 1.
What are the interrupt mailbox addresses for the 71321SA55PFI?
The 71321SA55PFI uses fixed interrupt mailbox addresses: writing to 7FEH (hex) sets the INTL flag, and writing to 7FFH sets the INTR flag. Clearing is performed by reading those same addresses with OE asserted - detailed in Truth Table II and Functional Description section on page 16 of the datasheet.
71321SA55PFI 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (14x14)
71321SA55PFI FAQ
1.How can I place an order for 71321SA55PFI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321SA55PFI 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 71321SA55PFI reliable?
The price and inventory of 71321SA55PFI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321SA55PFI is usually 5 days.
3.What payment methods are accepted for 71321SA55PFI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321SA55PFI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321SA55PFI?
71321SA55PFI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321SA55PFI 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 71321SA55PFI?
For technical support, including 71321SA55PFI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321SA55PFI requirements.
6.How does Aetrix verify that 71321SA55PFI is sourced from the original manufacturer or authorized distributors?
All 71321SA55PFI 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 71321SA55PFI meets industry standards.
7.What is the process for return or replacement of 71321SA55PFI?
All 71321SA55PFI units undergo pre-shipment inspection (PSI). If there is an issue with 71321SA55PFI, 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 71321SA55PFI part is unused and in its original packaging.
Return procedure for 71321SA55PFI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321SA55PFI Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
