IDT79RC4640, IDT79RC4640-180DU, IDT79RC4650

The IDT79RC4640 is a low-cost member of the Integrated Device Technology, Inc. RC4000 family, targeted to a variety of performancehungry embedded applications. The RC4640 continues the RC4000 tradition of high-performance through high-speed pipelines, high-bandwidth caches and bus interface, 64-bit architecture, and careful attention to efficient control. The cost of this performance is reduced by removing functional units frequently not required for many embedded applications.

The RC4640 supports a wide variety of embedded processor-based applications, such as internetworking equipment (routers, switches),office automation equipment (printers, scanners), and consumer multimedia game systems. Also, being upwardly software-compatible with the RC32300 family as well as bus- and upwardly software-compatible with the IDT RC4000 family, the RC4640 will serve in many of the same applications. And, the RC4640 supports applications that require integer digital signal processing (DSP) functions.

The RC64475 and RC64575 processors offer a direct migration path for designs based on IDT's RC4650 processors, through full pin and socket compatibility.

The RC4640 brings 64-bit performance levels to lower cost systems. High performance is preserved by retaining large on-chip two-way setassociative caches, a streamlined high-speed pipeline, high bandwidth, 64-bit execution, and facilities such as early restart for data cache misses.

These techniques allow the system designer over 3.2 GB/sec aggregate internal bandwidth, 500 MB/sec bus bandwidth, almost 352 Dhrystone MIPS, 89MFlops, and 133.5 M Mul-Add/sec. An array of tools facilitates rapid development of RC4640-based systems, allowing awide variety of customers access to the processor's high-performance capabilities while maintaining short time-to-market goals.

The extensions result in better code density, greater multiprocessing support, improved performance for commonly used code sequences in operating system kernels, and faster execution of floatingpoint intensive applications. All resource dependencies are made transparentto the programmer, insuring transportability among implementations of the MIPS instruction set architecture. In addition, MIPS-III specifies new instructions defined to take advantage of the 64-bit architecture of the processor.

Finally, the RC4640 also implements additional instructions, which are considered extensions to the MIPS-III architecture. These instructions improve the multiply and multiply-add throughput of the CPU, making it well suited to a wide variety of imaging and DSP applications.These extensions, which use opcodes allocated by MIPS Technologies for this purpose, are supported by a wide variety of development tools.

The MIPS integer unit implements a load/store architecture with single cycle ALU operations (logical, shift, add, sub) and autonomous multiply/divide unit. The 64-bit register resources include: 32 generalpurpose orthogonal integer registers, the HI/LO result registers for the integer multiply/divide unit, and the program counter. In addition, the onchip floating-point co-processor adds 32 floating-point registers, and a floating-point control/status register.

The IDT79RC4650 is a low-cost member of the IDT Microprocessor family, targeted to a variety of performance-hungry embedded applications. The RC4650 continues the IDT tradition of high-performance through high-speed pipelines, high-bandwidth caches and bus interface, 64-bit architecture, and careful attention to efficient control. The RC4650 reduces the cost of this performance relative to the RC4700 by removing functional units that are frequently unneeded for many embedded applications, such as double-precision floating point arithmetic and a TLB.

The RC4650 adds features relative to the RC4700, reflective of its target applications. These features enable system cost reduction (e.g., optional 32-bit system interface) as well as higher performance for certain types of systems (e.g., cache locking, improved real-time support, integer DSP capability).

The RC4650 supports a wide variety of embedded processor-based applications, such as consumer game systems, multi-media functions, internetworking equipment, switching equipment, and printing systems. Upwardly software-compatible with the RC3000 family, and bus- and upwardly software-compatible with the IDT RC4000/RC5000 family, the RC4650 will serve in many of the same applications, but, in addition supports other applications such as those requiring integer DSP functions.

The RC64475 and RC64575 processors offer a direct migration path for designs based on IDT's RC4650 processors, through full pin and socket compatibility.

The RC4650 brings 64-bit performance levels to lower cost systems. High performance is preserved by retaining large on-chip caches that are two-way set associative, a streamlined high-speed pipeline, highbandwidth, 64-bit execution, and facilities such as early restart for data cache misses. These techniques combine to allow the system designer 3.2GB/sec aggregate bandwidth, 1000 MB/sec bus bandwidth, 352 Dhrystone MIPS, 89 MFlops, and 133.5 M Multiply-add/second.

The RC4650 provides complete upward application-software compatibility with the IDT79RC32300™ and IDT79RC64xxx™ families of microprocessors. An array of development tools facilitates the rapid development of RC4650-based systems, enabling a wide variety of customers to take advantage of the high-performance capabilities of the processor while maintaining short time to market goals.

The 64-bit computing capability of the RC4650 enables a wide variety of capabilities previously limited by the lower bandwidth and bitmanipulation rates inherent in 32-bit architectures. For example, the RC4650 can perform loads and stores from cached memory at the rate of 8-bytes every clock cycle, doubling the bandwidth of an equivalent 32-bit processor. This capability, coupled with the high clock rate for the RC4650 pipeline, enables new levels of performance to be obtained from embedded systems.

This data sheet provides an overview of the features and architecture of the RC4650 CPU. A more detailed description of the processor is available in the IDT79RC4650 Processor Hardware User's Manual, available from IDT. Further information on development support, applications notes, and complementary products are also available from your local IDT sales representative.