User`s manual

MXGD Series CyberResearch

Motherboards

C.1 DIO Interface Introduction

The DIO connector on the MXGD is interfaced to GIO ports on the iTE Super I/O chipset.

The DIO has both 4-bit digital inputs and 4-bit digital outputs. The digital inputs and digital

outputs are generally control signals that control the on/off circuit of external devices or

TTL devices. Data can be read or written to the selected address to enable the DIO

functions.

NOTE:

For further information, please refer to the datasheet for the iTE Super

I/O chipset.

C.2 DIO Connector Pinouts

The following table describes how the DIO connector pins are connected to the Super I/O

GPIO port 1.

PIN NO. DESCRIPTION PIN NO. DESCRIPTION

1 GND 2 VCC

3 Output 3 4 Output 2

5 Output 1 6 Output 0

7 Input 3 8 Input 2

9 Input 1 10 Input 0

C.3 Assembly Language Samples

C.3.1 Enable the DIO Input Function

The BIOS interrupt call INT 15H controls the digital I/O. An assembly program to enable

digital I/O input functions is listed below.

MOV AX, 6F08H

Sets the digital port as input

INT 15H

Initiates the INT 15H BIOS call