My Inquiry
My Account
Renesas 71321LA20PF
- Part No.:
- 71321LA20PF
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 64-LQFP
- Datasheet:
-
71321LA20PF.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,063
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
71321LA20PF 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. It delivers 20 ns max read cycle time, 2V data retention in battery backup mode, and operates on single 5V ±10% supply across –40°C to +85°C industrial temperature range. It enables error-free 16-bit+ memory expansion when paired with IDT71421 SLAVE devices in embedded control systems.
For engineers reviewing the 71321LA20PF datasheet, 71321LA20PF pinout, 71321LA20PF application, or 71321LA20PF equivalent, key selection considerations include its MASTER-only BUSY output architecture, dual-interrupt mailbox addressing (7FEh/7FFh), low 1 µA full-standby current, and compatibility with PLCC/STQFP/TQFP packages for real-time co-processor memory sharing.
Technical Context
The 71321LA20PF implements fully asynchronous dual-port access with independent left/right address, control, and I/O buses. Its on-chip arbitration logic uses chip enable (CEL/CER) and address match detection-not R/W state-to assert BUSYL/BUSYR outputs, enabling deterministic port conflict resolution without external logic.
Interrupt functionality relies on dedicated mailbox addresses: writing to 7FEh sets INTL (left port flag), writing to 7FFh sets INTR (right port flag); clearing is performed by reading those same locations. The device supports battery backup operation at 2V with guaranteed data retention and sub-100 µA retention current-exclusive to LA variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), 16,384 total bits |
| Max Read Cycle Time | 20 ns - defines minimum clock period for synchronous interface integration |
| Data Retention Voltage | 2.0 V - enables direct connection to backup battery without regulator |
| Full Standby Current (ISB3) | 0.2 mA typ. at 5V - ultra-low power hold mode with CMOS-level inputs |
| Operating Temperature | –40°C to +85°C - qualified for industrial embedded environments |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible single 5V rail, no auxiliary supplies needed |
| Interrupt Mailbox Addresses | 7FEh (sets INTL), 7FFh (sets INTR) - fixed SRAM locations used as hardware signaling registers |
Pinout & Package
71321LA20PF is packaged in 52-pin STQFP (PPG52), measuring 10 mm × 10 mm × 1.4 mm, with exposed thermal pad. Pin assignments are identical across 52-pin variants (PLCC/STQFP) per IDT DSC-2691 Rev. 17.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0L–A10L | Left port address inputs | 11-bit address bus for left-side memory access (0–2047) |
| A0R–A10R | Right port address inputs | 11-bit address bus for right-side memory access (0–2047) |
| I/O0L–I/O7L | Left port bidirectional data | 8-bit data path; direction controlled by R/WL and OEL |
| I/O0R–I/O7R | Right port bidirectional data | 8-bit data path; direction controlled by R/WR and OER |
| CEL / CER | Chip enable (active low) | Port-select enable; controls power-down entry/exit per port |
| OEL / OER | Output enable (active low) | Enables I/O drivers only; does not affect internal power state |
| R/WL / R/WR | Read/write control (active low = write) | Determines data flow direction during enabled cycles |
| BUSYL / BUSYR | Open-drain BUSY flags | Outputs on MASTER (71321); require 270Ω pull-up; signal port contention |
| INTL / INTR | Interrupt flags (open-drain) | Asserted low on mailbox write; require pull-up; support inter-processor signaling |
| VCC / GND | Power and ground | Multiple VCC/GND pins ensure stable noise margin and thermal distribution |
Key Features
| Feature | Design Value |
|---|---|
| MASTER-only BUSY arbitration | Hardware-enforced write inhibition during address contention-no firmware overhead or external logic required |
| Dual interrupt mailboxes (7FEh/7FFh) | Zero-latency hardware signaling between processors using standard SRAM reads/writes |
| 2V data retention | Preserves memory contents during main power loss; eliminates need for external backup controller |
| 52-pin STQFP (PPG52) package | 10 mm × 10 mm footprint with thermal pad-optimized for space-constrained industrial PCBs |
| Industrial temperature range | Validated operation from –40°C to +85°C-suitable for motor drives, PLCs, and transportation systems |
| Low ISB3 standby current (0.2 mA) | Reduces system-level quiescent power in always-on monitoring applications |
Applications
| Industrial PLC Memory Buffer | Real-Time Motion Controller |
|---|---|
Use Scenario: Dual-CPU architecture where one CPU handles I/O scanning and another executes motion algorithms, requiring shared status and command buffers. IC Role / Device Role / Timing Role: MASTER dual-port SRAM provides synchronized, lock-free memory exchange via BUSY arbitration and interrupt mailboxes. Use Value: Eliminates software semaphores and polling; guarantees atomic 8-bit message passing with ≤20 ns latency between CPUs. |
Use Scenario: Coordinated multi-axis servo drive with separate position loop and trajectory planning processors. IC Role / Device Role / Timing Role: 71321LA20PF acts as timing-critical shared register bank-trajectory points written by planner, read by position loop at 10 kHz. Use Value: 20 ns access ensures position loop jitter remains below 100 ns; 2V retention preserves last commanded position during brownout. |
| Avionics Data Logger Interface | Medical Imaging Subsystem |
Use Scenario: Flight data recorder interfacing between sensor acquisition FPGA and ARM-based logging processor. IC Role / Device Role / Timing Role: MASTER SRAM buffers high-rate sensor streams while allowing non-blocking log file updates from host CPU. Use Value: BUSY logic prevents data corruption during simultaneous capture and save; 0.2 mA ISB3 extends battery-backed logging duration. |
Use Scenario: MRI subsystem with FPGA-based image reconstruction engine and DSP-based real-time correction unit. IC Role / Device Role / Timing Role: 71321LA20PF serves as low-latency coefficient exchange memory-FPGA writes calibration tables, DSP reads before frame processing. Use Value: Interrupt-driven mailbox (7FEh) signals table update completion in <25 ns, eliminating polling delay in 100+ fps imaging pipeline. |
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-20AXC | 2K × 16 organization; no built-in BUSY arbitration; requires external logic for contention management | Lacks integrated interrupt mailboxes and 2V retention; suited for wider-bus designs without arbitration needs | Select only if 16-bit data path is mandatory and external arbitration logic is acceptable |
| IDT71421LA20PF | SLAVE-only variant; BUSY pins are inputs (not outputs); no on-chip arbitration logic | Must be paired with 71321LA20PF in MASTER/SLAVE configuration; cannot operate standalone as MASTER | Use exclusively as expansion slave in 16-bit+ systems; never as drop-in replacement for 71321LA20PF |
Compared with CY7C024AV-20AXC and IDT71421LA20PF, the 71321LA20PF uniquely combines MASTER arbitration, dual interrupts, and 2V retention in a 2K × 8 format-making it irreplaceable for compact, self-contained dual-processor memory interfaces requiring deterministic timing and battery backup.
Availability
71321LA20PF is available at Aetrix Electronics and suitable for industrial PLCs, real-time motion controllers, avionics data loggers, and medical imaging subsystems requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for 71321LA20PF 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 IDT71321/71421 family was designed specifically for deterministic interprocessor communication in resource-constrained embedded systems-emphasizing hardware arbitration, low-power retention, and seamless MASTER/SLAVE scalability without external glue logic.
FAQ
What is the function of BUSYL and BUSYR on the 71321LA20PF?
BUSYL and BUSYR are open-drain outputs on the 71321LA20PF that signal port contention during simultaneous access to the same memory location. When asserted low, they inhibit writes on the respective port. Each requires a 270Ω pull-up resistor. These signals are exclusive to the MASTER device and are not present as outputs on SLAVE variants like IDT71421.
Does the 71321LA20PF support true dual-port concurrent read/write operations?
Yes-the 71321LA20PF supports fully asynchronous, independent read and write operations on left and right ports. However, when both ports access the same address, on-chip arbitration asserts BUSYL or BUSYR to block the later-arriving write, ensuring data integrity without software intervention or external logic.
How do the interrupt mailboxes (7FEh and 7FFh) work in the 71321LA20PF?
Writing to address 7FEh (hex) via the right port sets the INTL flag; writing to 7FFh via the left port sets the INTR flag. Reading either address clears the corresponding flag. These locations behave as standard SRAM cells-data written is user-defined-and provide hardware-level interprocessor signaling with ≤25 ns interrupt set time.
Can the 71321LA20PF operate without external pull-up resistors on BUSY and INT pins?
No-BUSYL, BUSYR, INTL, and INTR are open-drain outputs and require external pull-up resistors (270Ω recommended per IDT DSC-2691). Omitting them results in undefined logic levels and failed arbitration or interrupt signaling. This requirement is explicitly stated in Note 2 of the functional block diagram and Pin Configurations section.
Is the 2V data retention capability of the 71321LA20PF production-tested or characterization-only?
The 2V data retention specification for the 71321LA20PF is guaranteed but not production-tested per Table 6 (Data Retention Characteristics). It is validated through device characterization at TA = +25°C and VCC = 2.0V, with typical ICCDR of 100 µA and maximum 1500 µA (commercial grade). This capability is exclusive to LA variants and absent in SA versions.
71321LA20PF 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)
71321LA20PF FAQ
1.How can I place an order for 71321LA20PF through Aetrix?
Please submit a Request for Quotation (RFQ) for 71321LA20PF 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 71321LA20PF reliable?
The price and inventory of 71321LA20PF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71321LA20PF is usually 5 days.
3.What payment methods are accepted for 71321LA20PF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71321LA20PF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71321LA20PF?
71321LA20PF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71321LA20PF 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 71321LA20PF?
For technical support, including 71321LA20PF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71321LA20PF requirements.
6.How does Aetrix verify that 71321LA20PF is sourced from the original manufacturer or authorized distributors?
All 71321LA20PF 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 71321LA20PF meets industry standards.
7.What is the process for return or replacement of 71321LA20PF?
All 71321LA20PF units undergo pre-shipment inspection (PSI). If there is an issue with 71321LA20PF, 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 71321LA20PF part is unused and in its original packaging.
Return procedure for 71321LA20PF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71321LA20PF 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…
