没有合适的资源?快使用搜索试试~ 我知道了~
gop overview
4星 · 超过85%的资源 需积分: 33 17 下载量 165 浏览量
2013-08-04
15:28:26
上传
评论 1
收藏 1.45MB PDF 举报
温馨提示
试读
38页
Agenda •VGA HW •VBIOS Background •Why GOP ? •GOP Technical Concept •BIOS Consideration •Summary
资源推荐
资源详情
资源评论
GOP Overview
Session Goals
•Describe VGA HW and VBIOS background
•Introduce fundamental principles of GOP implements
•Provide general terms and concepts of GOP
−These terms and concepts are the basis of understanding
UEFI and will be built upon in following sessions.
Agenda
•VGA HW
•VBIOS Background
•Why GOP ?
•GOP Technical Concept
•BIOS Consideration
•Summary
VGA HW
The VGA can be divided in several parts . The following simplified diagram
shows which units are responsible for which parts:
Simplified Diagram
Frame Buffer (Video Memory)
– The component of the video hardware that stores the pixels and information to be displayed on the monitor.
– The center of the video hardware, as nearly all operations are performed on or using this data. The frame buffer is a form of
RAM, which is typically located outside the main graphics chip and are implemented using DRAM chips.
– The amount of video memory that is present determines the maximum resolution that the hardware can generate.
– The frame buffer is usually mapped into a region of the host CPU's address space allowing it to be accessed as if it were a
portion of the main memory.
Graphics Controller
– Video chipset's host interface to the frame buffer, and is part of the main graphics chip or chips.
– It allows the host CPU to manipulate the frame buffer in a fashion suited to the task of graphics operations.
– It allows certain methods of access that are designed to reduced the CPU requirements for performing standard video
operations.
Sequencer
– It is responsible to convert video memory to color indexes. Like the graphics controller, it has some special addressing logic,
which is designed to iterate over the memory in a sensible manner to produce images out of video memory data.
– The Sequencer either operates in text (alphanumeric) mode or graphics mode.
CRT Controller
– The Cathode Ray Tube Controller, or CRTC, is the unit to create a video signal from the data produced by the DAC.
DAC & Palette(Color Logic)
– The VGA's DAC subsystem accepts an 8 bit input from the attribute subsystem and outputs an analog signal that is presented
to the display circuitry.
– Internally it contains 256 18-bit memory locations that store 6 bits each of red, blue, and green signal levels which have
values ranging from 0 (minimum intensity) to 63 (maximum intensity.) The DAC hardware takes the 8-bit value from the
attribute subsystem and uses it as an index into the 256 memory locations and obtains a red, green, and blue triad and
produces the necessary output.
VGA HW
Terminology
剩余37页未读,继续阅读
资源评论
- devin_xiao2014-02-19GOP的基本介绍,还可以
hgf1011
- 粉丝: 380
- 资源: 16
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功