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Automatic Customization Method for Parameters of Analog-to-Digital Conversion

IP.com Disclosure Number: IPCOM000112587D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 89K

Publishing Venue

IBM

Related People

Nishimura, H: AUTHOR [+3]

Abstract

This article describes an Automatic Customization Method for adjusting several parameters of an 'analog video interface/digital video interface conversion circuit' automatically. This circuit is used as an interface circuit between a digital interface display device, such as a liquid crystal display, and a conventional analog video port of the system unit such as a video port of the Video Graphics Array in an IBM Personal Computer (PC) compatible system. The following items are some examples of the parameters: reference voltage of an A/D converter, phase between sampling clock and sync signal (Hsync, V sync, etc.) and backporch width, etc. The adjusted parameters are stored in a storage device, such as EEPROM, Diskdrive, etc., and they will be restored at every setup sequence.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Automatic Customization Method for Parameters of Analog-to-Digital
Conversion

      This article describes an Automatic Customization Method for
adjusting several parameters of an 'analog video interface/digital
video interface conversion circuit' automatically.  This circuit is
used as an interface circuit between a digital interface display
device, such as a liquid crystal display, and a conventional analog
video port of the system unit such as a video port of the Video
Graphics Array in an IBM Personal Computer (PC) compatible system.
The following items are some examples of the parameters: reference
voltage of an A/D converter, phase between sampling clock and sync
signal (Hsync, V sync, etc.) and backporch width, etc.  The adjusted
parameters are stored in a storage device, such as EEPROM, Diskdrive,
etc., and they will be restored at every setup sequence.

      Analog video output signals from PC are slightly different
among PC system units.  The video control circuit in the system unit
might be different according to the types of the system.  The
electrical characteristics of the components in the video control
circuit, such as graphic controller, digital/ analog converter, etc.,
are not completely the same, even in the same types of system units.
Therefore, the parameters of the analog/digital conversion circuit
shall be adjusted unit-by-unit to increase the accuracy of
analog/digital conversion.

      The functional block diagram in the Figure shows an exemplary
implementation of the Automatic Customization Method.  The block
diagram consists of 2 major parts: one is the Customization Screen
Display Program (*1) (Customization Program), and the other part is
Customization Circuit Block (*2), which is implemented in the
analog/digital conversion circuit (*3).  The Customization Start
Switch (*4) is used for starting the Customization Sequencer (*5).
Users who want to customize the parameters of the analog/digital
conversion circuit execute the Customization Screen Display Program
on the target system unit. ...