Chapter 3 – DFI CR902-B User Manual

Page 24

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Chapter 3 Hardware Installation

24

Chapter 3

Signal

Pin#

Pin Type

Pwr Rail /Tolerance

PU/PD

Description

VGA_RED

B89

O Analog

Analog

PD 150:

Red for monitor. Analog output

VGA_GRN

B91

O Analog

Analog

PD 150:

Green for monitor. Analog output

VGA_BLU

B92

O Analog

Analog

PD 150:

Blue for monitor. Analog output

VGA_HSYNC

B93

O CMOS

3.3V / 3.3V

Horizontal sync output to VGA monitor

VGA_VSYNC

B94

O CMOS

3.3V / 3.3V

Vertical sync output to VGA monitor

VGA_I2C_CK

B95

I/O OD CMOS 3.3V / 3.3V

PU 2.2K: to 3.3V

DDC clock line (I2C port dedicated to identify VGA monitor capabilities)

VGA_I2C_DAT

B96

I/O OD CMOS 3.3V / 3.3V

PU 2.2K: to 3.3V

DDC data line.

Signal

Pin#

Pin Type

Pwr Rail /Tolerance

PU/PD

Description

I2C_CK

B33

I/O OD CMOS 3.3V Suspend/3.3V

PU 2.2K: to 3.3V
Suspend

General purpose I2C port clock output

I2C_DAT

B34

I/O OD CMOS 3.3V Suspend/3.3V

PU 2.2K: to 3.3V
Suspend

General purpose I2C port data I/O line

VGA Signals Descriptions

I2C BUS Signal Descriptions

Signal

Pin#

Pin Type

Pwr Rail /Tolerance

PU/PD

Description

SPKR

B32

O CMOS

3.3V / 3.3V

Output for audio enunciator - the "speaker" in PC-AT systems.
This port provides the PC beep signal and is mostly intended for
debugging purposes.

WDT

B27

O CMOS

3.3V / 3.3V

Output indicating that a watchdog time-out event has occurred.

KBD_RST#

A86

I CMOS

3.3V / 3.3V

PU 10K: to 3.3V

Input to Module from (optional) external keyboard controller that can force a reset. Pulled high on the Module. This is a legacy artifact
of the PC-AT.

KBD_A20GATE

A87

I CMOS

3.3V / 3.3V

PU 10K: to 3.3V

Input to Module from (optional) external keyboard controller that can be used to control the CPU A20 gate line. The A20GATE restricts
the memory access to the bottom megabyte and is a legacy artifact of the PC-AT.Pulled high on the Module.

Miscellaneous Signal Descriptions

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