Renesas IDT79R3041-20PF

Overview

IDT79R3041-20PF from Integrated Device Technology is a 32-bit MIPS RISC microprocessor with integrated instruction cache (2 kB), data cache (512 B), programmable bus interface, on-chip DMA arbiter, and 24-bit timer. It operates at 20 MHz, delivers 20 MIPS performance, and supports 8-/16-/32-bit memory port widths - enabling low-cost embedded systems such as laser printer controllers and PDL interpreters.

For engineers reviewing the IDT79R3041-20PF datasheet, IDT79R3041-20PF pinout, IDT79R3041-20PF application, or IDT79R3041-20PF equivalent, key selection criteria include its PLCC-84 package, double-frequency clock input (ClkIn), SysClk output timing feedback, ALE-controlled address/data multiplexing, and software compatibility with the IDT RISController family including R3051 and R3081.

Technical Context

The IDT79R3041-20PF implements the MIPS-I ISA with a five-stage pipeline and binary compatibility to the IDT79R3000A CPU core. Its execution engine sustains near single-cycle ALU operations and features autonomous multiply/divide hardware separate from the ALU.

It integrates a System Control Coprocessor (CP0) managing exception handling, physical address mapping without TLB, cache configuration, bus timing control, and programmable port width per memory sub-region - all configurable via CP0 registers at reset or runtime.

Key Specifications

Pinout & Package

Package: 84-pin Plastic Leaded Chip Carrier (PLCC), cavity-down, lead-free compatible per IDT documentation. Thermal resistance ØCA = 29°C/W at 0 ft/min airflow.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RISC microprocessor applications.

Compared with IDT79R3051-20PF and IDT79R3081-25PF, the IDT79R3041-20PF delivers optimal cost-performance balance for fixed-function embedded systems where virtual memory and hardware FP are unnecessary - retaining full software compatibility while minimizing BOM and layout complexity.

Availability

IDT79R3041-20PF is available at Aetrix Electronics and suitable for laser printer controllers, PDL interpreter systems, industrial HMI terminals, networked peripheral controllers, and embedded imaging subsystems requiring stable component supply across long production lifecycles.

Supply support for IDT79R3041-20PF 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 U.S.-based semiconductor company specializing in high-performance timing, memory interface, and embedded processor solutions before its acquisition by Renesas Electronics in 2019.

The IDT79R3041-20PF belongs to the RISController™ family - designed specifically to bring MIPS RISC performance to cost-sensitive embedded applications through high integration (cache, DMA, timer, programmable bus) in low-pin-count PLCC packaging.

FAQ

What is the maximum operating frequency of the IDT79R3041-20PF?

The IDT79R3041-20PF is rated for 20 MHz operation, corresponding to a 20 MHz double-frequency ClkIn input. It achieves 20 MIPS performance at this frequency when executing from on-chip caches. The "-20" suffix explicitly denotes the 20 MHz speed grade; higher-speed variants (e.g., IDT79R3041-25PF) exist but are not pin- or thermally identical.

Does the IDT79R3041-20PF include a memory management unit (MMU)?

No, the IDT79R3041-20PF does not include an MMU or TLB. It implements base virtual-to-physical address mapping without page tables, supporting distinct kernel/user modes via physical memory protection only. For MMU functionality, IDT offered the pin-compatible IDT79R3051-20PF with a 64-entry TLB - a separate part requiring different CP0 register initialization.

How does the IDT79R3041-20PF handle mixed-width memory systems?

The IDT79R3041-20PF uses its Port Size Control Register (in CP0) to partition the physical address space into sub-regions, each assigned 8-, 16-, or 32-bit port width. During accesses, the bus interface unit automatically performs data packing/unpacking - e.g., reading four bytes from a 16-bit DRAM as two sequential transfers - transparently to software.

What is the function of the SysClk pin on the IDT79R3041-20PF?

The SysClk pin outputs a buffered, low-skew version of the internal system clock referenced to the CPU's timing domain. It is used to synchronize external logic (e.g., DRAM controllers, latches) and provides <2 ns rise/fall times under specified load. Critically, internal bus interface timing (e.g., ALE hold) is locked to SysClk, ensuring robust operation across voltage/temperature variations.

Can the IDT79R3041-20PF boot directly from an 8-bit PROM?

Yes, the IDT79R3041-20PF supports booting from 8-bit, 16-bit, or 32-bit PROMs without external logic. At reset, the Port Size Control Register defaults to 8-bit width for the boot region (0x00000000–0x00FFFFFF), and the bus interface unit handles byte-wide instruction fetches and automatic data alignment - enabling minimal-cost boot architectures.