PR31500

PR31500 Processor is a single-chip, low-cost, integrated embedded processor consisting of MIPS R3000 core and system support logic to interface with various types of devices.

PR31500 consists of a MIPS R3000 RISC CPU with 4 KBytes of instruction cache memory and 1 KByte of data cache memory, plus integrated functions for interfacing to numerous system components and external I/O modules. The R3000 RISC CPU is also augmented with a multiply/accumulate module to allow integrated DSP functions, such as a software modem for high-performance standard data and fax protocols.

The PR31500 processor can support both Little and Big Endian operating systems. In addition the PR31500 provides a memory management unit with an on-chip Translation Look aside Buffer (TLB) for very fast virtual to physical address translation.

PR31500 also contains multiple DMA channels and a high-performance and flexible Bus Interface Unit (BIU) for providing an efficient means for transferring data between external system memory, cache memory, the CPU core, and external I/O modules. The types of external memory devices supported include dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), static random access memory (SRAM), Flash memory, read-only memory (ROM), and expansion cards (e.g., PCMCIA). PR31500 also contains a System Interface Module (SIM) containing integrated functions for interfacing to numerous external I/O modules such as liquid crystal displays (LCDs), the UCB1100 (which handles most of the analog functions of the system, including sound and telecom codecs and touchscreen ADC), ISDN/high-speed serial, infrared, wireless peripherals, etc. Lastly, PR31500 contains support for implementation of power management, whereby various PR31500 internal modules and external subsystems can be individually (under software control) powered up and down.