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1
CHAPTER 1 INTRODUCTION
The V
R
4101 is one of the RISC (reduced instruction set computer) microprocessor V
R-
Series products
manufactured by NEC. It is designed around the RISC architecture developed by MIPS. This 64-bit
microprocessor mainly consists of the V
R
4100 CPU core (containing a cache memory, high-speed sum-
of-products operation unit, and address management unit), DMA, and peripheral circuit interface units
(such as a serial interface, keyboard interface, IrDA interface, touch panel interface, and real-time clock)
required by battery-driven information units.
The V
R
4101 microprocessor is compatible with the MIPS I, MIPS II, and MIPS III Instruction Set
Architecture (ISA). However, none of the floating-point, LL, LLD, SC and SCD instructions is supported.
This microprocessor does not provide on-chip support for a secondary cache or multiprocessing, and
floating-point operation.
1.1 CHARACTERISTICS
The V
R
4100 has the following characteristics:
"
MIPS I, II, III instruction sets (without the FPU, LL, and SC instructions from the VR4000 family
instruction set) compatible
"
Internal 64-bit processing
"
32-bit physical address space and 40-bit virtual address space
"
Internal operating frequency: 33 MHz
"
Optimized 5-stage pipeline, 2-Kbyte instruction cache and 1-Kbyte data cache, and 32-double-entry
TLB
"
Write-back cache for reducing store operations that use the system bus
"
madd16 and dmadd16 instructions for executing a sum-of-products operation of 16-bit data x 16-bit
data + 64-bit data within one clock cycle
"
Effective power management features, which include the following four operating modes:
Full Speed mode
Standby mode
Suspend mode
Hibernate mode
"
No floating-point functions
"
No secondary cache, multiprocessor function (LL, LLD, SC, or SCD instruction)
"
All clock pulses for internal operations generated from a 32-kHz crystal
"
Built-in clock generator
"
Built-in PLL for frequency multiplication by 2024
"
External bus frequency of 16 MHz
"
Built-in 8-Mbyte DRAM and 16-Mbyte masked ROM interfaces
"
Built-in LCD, keyboard, and touch panel interfaces
"
Built-in 5-channel DMA controller