Technical Information 1-17
Intel Pentium P55CLM Microprocessor
The 166 MHz Intel Pentium microprocessor with MMX technology used in the NEC Versa
series computer is built on Intel’s advanced 2.5V BiCMOS silicon technology. The CPU
has on-chip dual-processing, a local multiprocessor interrupt controller, and power man-
agement features. NEC adopted the chip specifically for its pipelined Floating Point Unit
(FPU), and local interrupt management.
M-Triton System Controllers
NEC implements Intel’s Mobile Triton technology (MTDP 8249TX and MTSC 82371TX)
for several of the notebook’s subsystems including the DRAM controller, Second Level
Cache Controller and PCI Bus interface. The Mobile Triton PCI set features include:
direct mapped organization write-back policy
fully synchronous 33 MHz PCI bus interface.
256K X Flash ROM
The N28F020 flash ROM is a 32-pin, plastic lead chip carrier (PLCC). The chip allows easy
updates to the system's BIOS if needed. More specifically, the ROM is flashed electroni-
cally, installing the latest BIOS revisions to the system. It is possible to reprogram the BIOS
up to 100,000 times. See Section 2, Setup and Operation, for BIOS update procedures.
The N28F020 provides the system upgrade capability as well as the following:
256 KB memory
Quick-Pulse Programming Algorithm
150 nanoseconds (ns) maximum access time
ETOX Nonvolatile flash technology
CMOS low power consumption
ROM BIOS
The system uses a Flash ROM known as the system's ROM BIOS to store machine lan-
guage programs. The BIOS size is 256 KB, consisting of the system utility (for the Auto
Setup), system BIOS, video BIOS, and Power Management.
The BIOS programs execute the power-on self-test (POST), initialize CPU controllers, and
interact with the LCD indicator panel, diskette drive, hard drive, communication devices
and peripherals. The system BIOS also contains Auto Setup and provides VGA controller
support. The ROM BIOS is copied into RAM (shadowing) for optimum performance.
The ROM BIOS contains both the system and video BIOS. The system BIOS is located in
the upper portion of the device; video BIOS is located in the lower portion. System BIOS is
located between F0000h-FFFFFh.
