Supervisor: Fearghal Morgan Analog Devices: Ray Carter Dept. Electronic Engineering NUIG 23 April 2008 Software Driver for ADV7800 Video Decoder Nóirín

Supervisor: Fearghal Morgan

Analog Devices: Ray Carter

Dept. Electronic Engineering NUIG

23 April 2008

Software Driver for ADV7800 Video Decoder

Nóirín Duggan

Project Outline

3


Nóirín Duggan


-> Project Outline

-> The software driver system

-> Implementation

-> Challenges

-> Outcome

Format of Presentation


Nóirín Duggan


Project Outline

Project Outline

3


Nóirín Duggan


The aim of this project was to create a basic operational software driver for the Standard Definition core of the ADV7800 Analog Devices video decoder which would dynamically configure the device when a CVBS or SVideo input is detected. The driver had to be clear, concise and portable allowing the end user to interact with the decoder without needing detailed knowledge of the part.

Project Outline


Nóirín Duggan


The Software Driver System


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ADV7800

RCA jack/Din Connector

TV

Encoder/HDMI

GUI

VCR/DVD

uB

Push Buttons

Spartan 3 board

ADV7800 Evaluation Board

Analog Standard Definition interfaces:

S-Video/CVBS interface transmitting PAL/NTSC/

SECAM

GUI provides read back on device

driver, stating that it is running etc,,

source recognition, report on standard, quality of source,

read back on noise on input signal

Microblaze processor 32-bit Harvard

Reduced Instruction Set Computer architecture;

Only as much processor as you

need!

Spartan 3 boardUART, SRAM, Timer,

Pushbuttons

ADV7800 video decoder. Designed to showcase new 3D comb filter.

Supports SD standards NTSC, PAL, SECAM and component standards 525i, 625i, 525p, 625p, 720p, 1080i

and computer graphics modes

I2C communication lines

The hardware elements of the System


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Software Driver System

Handler/Task Functions LibraryLAYER 3

Feature Functions LibraryLAYER 2

Register Access Function LibraryLAYER 1

Application

GPIO, I2C driver

LAYER 0

LAYER 4


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User Interaction Model

Start

User -> Enables system-> Selects backend video processing device

User inserts interface cable

Driver configures decoder and other evaluation board

devices for selection

GUI provides readback information on driver


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Main Loop of System

Initialise HW System InitMB()

Start

Initialise SW System

Init_sys()

Is Driver Enabled?

Get Driver ModeGet_sys_mode()

Is mode==HRX

Is mode ACP?

Is Mode SDP?

PushButtonHandler()

SDP_main()

ACP_Main()

HRX_main()

Yes

Yes

No

Yes

No

Yes

UartCommandHandler()


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Application System Controller -> Layer 0

Start

Get system interface()

Graphics?

Component?

Svideo?

Set mode = ACPSet interface =

componentInitialise ACP application

Set mode = SDPSet interface = Svideo

Initialise SDP application

Set mode = SDPSet interface = CVBS

Initialise SDP application

CVBS?

Set mode =ACPSet interface =Graphics

Initialise ACP application

End


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Application Initialiser

Start

Reset microblaze

Configure Interrupts

Connect Callback function

Initialise Decoder

Set up input interface

End


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Flow of Control

Initialise HW System InitMB()

Start

Initialise SW System

Init_sys()

Is Driver Enabled?

Get Driver ModeGet_sys_mode()

Is mode==HRX

Is mode ACP?

Is Mode SDP?

PushButtonHandler()

SDP_main()

ACP_Main()

HRX_main()

Yes

Yes

No

Yes

No

Yes

UartCommandHandler()

Control is returned to main loop, where the

user selected application runs


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Application Main

Start

Run SDP driver interrupt handler

Has 10ms Timerexpired

Run SDP driver video handler

Reset Timer

End

Check if Interrupt has occurred


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Software Driver Handler Functions




Application

GPIO, I2C driver

LAYER 0

LAYER 4

Software Driver Interrupt handler

Called by application, reads status of standard definition video detect register, if set sets video state machine to video detected

Video Handler

Called by application, reads value of video state machine if valid video detected it retrieves standard identification from the decoder and passes it to application


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Application Video Handler

Start

Configure ADV7800

End

Configure Evaluation board devices


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Graphical User Interface


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Implementation Methodology


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General Strategy for implementation

• Disassemble the project into its constituent subsystems

• Solve individually

• Glue together


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General Strategy for implementation

• Disassemble the project into its constituent blocks

• Solve individually

• Glue together

What were the subsystems?


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The blocks of the System

Handler/Task Functions Library

Feature Functions Library

Register Access Function Library

Application

GPIO, I2C driver

The Driver


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Mini Driver 1.0




Application

GPIO, I2C driver

The Driver Mini driver1.0


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Mini Driver 2.0




Application

GPIO, I2C driver

The Driver

Lower level Application: microblaze functions, push button handler etc

Mini driver1.0

Mini driver2.0


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SD driver 1.0




Application

GPIO, I2C driver

The Driver

Top Level Application: config Video receiver etc


Mini driver1.0

Mini driver2.0

SD driver1.0


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SD driver 2.0




Application

GPIO, I2C driver

The Driver

Top Level Application: config Video receiver etc


Mini driver1.0

Mini driver2.0

SD driver1.0 SD_driver2.0


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Successful Strategy?


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Challenges


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Challenges

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Challenges

• No previous experience of either embedded system design/EDK tools or microblaze


Nóirín Duggan


Challenges

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Challenges


• Limited knowledge of ADV7800 video decoder


Nóirín Duggan


Challenges

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Challenges


• Limited knowledge of ADV7800 video decoder

• Limited experience of large software projects/device drivers/C programming


Nóirín Duggan


Challenges

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Understanding the structure of the Driver




Application

GPIO, I2C driver

LAYER 0

LAYER 4


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Summary of Achievements


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• Completed the spec


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• Learned how to use Xilinx tools to create a microblaze soft core processor


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• Combined this with software element to create a viable embedded system for a real world application


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• Combined this with software element to create a viable embedded system

• Learned about software development i.e. creating reusable, portable projects


Nóirín Duggan


Conclusion

Documents

Supervisor: Fearghal Morgan Analog Devices: Ray Carter Dept. Electronic Engineering NUIG 23 April 2008 Software Driver for ADV7800 Video Decoder Nóirín