Renesas IDT79RV4640-200DU

Overview

IDT79RV4640-200DU from Integrated Device Technology is a 3.3V, 64-bit MIPS-III RISC microprocessor with integrated floating-point coprocessor, 8KB instruction and 8KB data caches, and 200MHz pipeline clock. It delivers 352 Dhrystone MIPS, 89 MFlops single-precision performance, and supports integer multiply-accumulate at 133.5M ops/sec - deployed in embedded internetworking equipment, office automation systems, and multimedia game platforms.

For engineers reviewing the IDT79RV4640-200DU datasheet, IDT79RV4640-200DU pinout, IDT79RV4640-200DU application, or IDT79RV4640-200DU equivalent, key selection considerations include its 32-bit synchronized system bus interface, on-chip cache locking for deterministic real-time response, MIPS-III binary compatibility with RC4650/RC4700, and absence of native double-precision floating-point support.

Technical Context

The IDT79RV4640-200DU implements a 5-stage integer pipeline with autonomous multiply/divide unit and dedicated MUL/MAD instructions optimized for DSP workloads. Its floating-point coprocessor executes IEEE 754 single-precision operations (ADD/SUB/MUL/DIV/SQRT) with latencies of 4–32 cycles and supports overlapped execution with the integer unit.

Virtual-to-physical address translation uses CP0 base-bounds registers for user-mode memory management without TLB, while kernel-mode addresses undergo fixed translation. Cache subsystem features two-way set-associative 8KB instruction and data caches with write-back policy, parity protection, and lockable Set A for time-critical code retention.

Key Specifications

Pinout & Package

Package: 256-pin Ceramic Pin Grid Array (CPGA), 35.56 mm × 35.56 mm, 1.27 mm pitch - identical to RC64474/RC64574 socket compatibility.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 64-bit embedded RISC processor applications.

Compared with IDT79RV4640-200DU, the IDT79RC4640-200DU requires 5V supply and lacks cache locking, while IDT79RC4650-200DU adds double-precision FPU and higher integer throughput - making the RV variant optimal for cost-sensitive, 3.3V, real-time embedded designs needing deterministic cache behavior.

Availability

IDT79RV4640-200DU is available at Aetrix Electronics and suitable for router control planes, printer engine controllers, interactive game consoles, and industrial HMI terminals requiring stable component supply across extended production lifecycles.

Supply support for IDT79RV4640-200DU 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, Inc. (IDT) was a fabless semiconductor company specializing in timing, memory interface, RF, and high-performance embedded processors before its acquisition by Renesas Electronics in 2019.

The IDT79RV4640-200DU belongs to the RC4000 family of embedded RISC processors designed for cost-sensitive, high-throughput applications in networking, office automation, and consumer multimedia where 64-bit performance must coexist with 32-bit system economics.

FAQ

What is the operating voltage of the IDT79RV4640-200DU?

The IDT79RV4640-200DU operates at 3.3V nominal supply voltage for both core and I/O circuits. The "RV" prefix in the part number explicitly denotes the 3.3V variant per IDT's naming convention, distinguishing it from the 5V "R" series (e.g., IDT79RC4640-200DU) and mixed-voltage "RC" variants.

Does the IDT79RV4640-200DU support double-precision floating-point arithmetic?

No, the IDT79RV4640-200DU does not implement double-precision floating-point operations in hardware. Attempts to execute double-precision instructions trigger a trap to the integer unit, requiring software emulation. Its floating-point coprocessor is strictly single-precision IEEE 754 compliant, matching the RC4700's single-precision unit but omitting the RC4700's double-precision capability.

Is the IDT79RV4640-200DU pin-compatible with other RC4000 family processors?

Yes, the IDT79RV4640-200DU is socket-compatible with IDT RC64474 and RC64574 processors and shares the same 256-pin CPGA package outline. However, it is not pin-compatible with RC4650 derivatives that integrate double-precision FPU - those require different power and signal routing despite mechanical footprint similarity.

How does cache locking function in the IDT79RV4640-200DU?

In the IDT79RV4640-200DU, cache locking is implemented via CP0 register configuration to fix Set A of both instruction and data caches. Once locked, lines in Set A cannot be overwritten by cache misses, preserving time-critical code or data. This ensures deterministic worst-case execution time for real-time tasks without requiring full cache disable or external SRAM.

What boot-time configuration options are available for the IDT79RV4640-200DU?

The IDT79RV4640-200DU initializes fundamental modes via a 256-bit serial boot-time stream read at VCCOK assertion. This low-frequency interface configures PLL multiplier (2×–8×), bus width (32-bit), cache policies, and memory mapping attributes. Configuration bits are typically stored in external EPROM or generated by system ASIC, enabling flexible system-level tuning without mask changes.