1 OVERVIEW................................................................................................................................................ 1-1
General ........................................................................................................................................................ 1-1
Specifications ............................................................................................................................................... 1-2
Memory Map ................................................................................................................................................ 1-6
I/O Port Map................................................................................................................................................. 1-7
Interrupt Level .............................................................................................................................................. 1-8
Pin assignments........................................................................................................................................... 1-9
2 Description of Operation ............................................................................................................................ 2-1
JS-170FR Block Diagram ............................................................................................................................ 2-1
2.1.1
2.1.2
2.1.2.1
FW82371EB Pin Assignment .................................................................................................. 2-3
2.1.2.2
2.1.2.3
IDE interface .......................................................................................................................... 2-10
2.1.2.4
USB interface......................................................................................................................... 2-12
2.1.3
Main RAM circuit....................................................................................................................... 2-13
2.1.4
BIOS ROM................................................................................................................................ 2-14
2.1.5
IT8673F circuit .......................................................................................................................... 2-15
2.1.5.1
IT8673F Pin Assignment ....................................................................................................... 2-16
2.1.5.2
Serial port (COM1, 2)............................................................................................................. 2-18
2.1.5.3
2.1.5.4
FDD interface circuit .............................................................................................................. 2-21
2.1.5.5
2.1.5.6
2.1.6
Serial port (COM3, 4)................................................................................................................ 2-26
2.1.7
VGA circuit (Refer to the page 4-4.) ......................................................................................... 2-28
2.1.7.1
SM710 Pin Assignment ......................................................................................................... 2-29
2.1.7.2
2.1.7.3
Back-Lite control circuit ......................................................................................................... 2-34
2.1.7.4
CRT interface ........................................................................................................................ 2-35
2.1.8
2.1.9
Hardware reset circuit............................................................................................................... 2-37
2.1.10
Clock......................................................................................................................................... 2-38
CONTENTS