71321LA35J

Memory IC Overview

The Renesas Electronics Corporation 71321LA35J is a high-speed, asynchronous dual-port static random-access memory (SRAM) device. It features a storage capacity of 16 kilobits organized as 2K words by 8 bits. The component supports simultaneous independent access to the same memory location from two separate ports, facilitating efficient interprocessor communication without external arbitration logic. It operates on a single 5V power supply with TTL-compatible inputs and outputs. Key electrical parameters include an access time of 35 nanoseconds and a write cycle time of 35 nanoseconds. The device is housed in a 52-pin Plastic Leadless Chip Carrier (PLCC) package.

Memory IC Feature Summary

• True dual-ported memory architecture enabling simultaneous read/write access to identical addresses from both ports.
• Integrated internal interrupt logic for direct port-to-port signaling and status flagging.
• On-chip automatic bus arbitration logic eliminates the need for external discrete control circuitry.
• Supports battery backup operation with data retention down to 2V for non-volatile state preservation.

Memory IC Applications

• Interprocessor communication interfaces between microprocessors or digital signal processors.
• Master/Slave dual-port RAM configurations for expanding data bus widths to 16 bits or greater.
• High-speed cache memory buffers requiring concurrent host and peripheral access.
• Real-time data logging systems utilizing battery-backed volatile memory.

Memory IC Procurement Notes

Verify component authenticity through authorized distributors due to potential obsolescence. Confirm specific suffix designations match required temperature ranges and package variants. Check for RoHS compliance status as older batches may not meet current environmental standards. Validate lead times carefully as availability may be limited. Ensure proper handling procedures are followed given moisture sensitivity classification.

Memory IC Selection Notes

Select this component when concurrent bidirectional data transfer is required without external arbitration hardware. Consider the 35ns access speed for applications demanding rapid response times. Evaluate the 52-pin PLCC package constraints against available PCB real estate. Compare against single-port alternatives if simultaneous access is unnecessary to reduce cost. Verify voltage compatibility with existing 5V system rails.

Memory IC Part Context

This part belongs to the IDT/Renesas 71321 series of dual-port SRAMs. It shares architectural similarities with the 71301 and 71421 models but offers higher density. The series is designed for embedded systems requiring reliable, fast memory sharing between multiple processing units. It represents a legacy solution for parallel interface designs before widespread adoption of serial protocols.

Memory IC Replacement Considerations

Direct pin-to-pin replacements may include the IDT71321SA35J or IDT71321LA35J variants. Verify functional equivalence regarding interrupt logic and arbitration features. Cross-reference datasheets for timing parameter differences. Consider newer generation dual-port SRAMs if lower power consumption is critical.