FPGA-Based Arcade Emulation
description
Transcript of FPGA-Based Arcade Emulation
FPGA-Based Arcade
EmulationDanny Funk, Cory Mohling, Tony
Milosch, David Gartner, John Alexander
Advisor: Philip JonesClient: Joseph Zambreno
Overview
Project Plan and Design
Design Challenges
2nd Semester Implementation
Final Results
Project Objective• Goals
o Showcase the capabilities of reconfigurable computing platforms
o Have a system that can be used for demonstrations
• Problemo Demonstrating
reconfigurable computing to non-technical users
o Demonstrate capabilities in captivating way
Conceptual Solution• FPGA Capabilities
o Continue 09/10 Senior Design team’s NES Emulation through FPGA
o Entire NES and game selection contained on single FPGA board
• Presentationso Have wide selection of
playable gameso Create arcade machine that
can be put on display
Concept Diagram
Controls (I/O)
Boot loaderCompact Flash Card
Functional Requirements
• Emulator must support the instruction set used by the original NES System
• All NES-specific emulation must be performed entirely in hardware
• Physical interface shall support 2-player arcade style controls
Functional Requirements
• Graphical interface must allow for selection of all available games on compact flash card
• Boot loader must read ROM files and initialize emulator memories
• Cabinet must support 100 lb monitor, and run on standard 120 VAC power
Non-Functional Requirements
• All emulator components shall be implemented as individual modules
• Cabinet shall be safe for all age groups• Users’ interaction with boot loader shall be
understandable without additional help• Cabinet shall be a vintage style arcade
cabinet to house the system• Cabinet shall be durable to withstand
demonstrations
Considerations• Constraints
o System has to be designed around NES ROM files and NES instruction set
o Only a limited amount of logic on FPGA board
o Cabinet should be able to be moved from building to building on campus
• Technologyo Using new monitor technology with old NES
o Interfacing with arcade controls
Market Survey• Another project currently exists (Veri NES).
The source is not available.• Various software emulators are available
and will help with understanding the NES.• Researched how similar arcade cabinets
have been built. • Took measurements of button layouts from
original arcade cabinets.
Risks and Mitigations• Unfamiliarity with FPGA coding and NES
Architectureo Research with assistance of advisor
• Audio may require CPU to be rewritteno Start early on Audio
• Unforeseen extra design requiredo Start Early on FPGA work
• Little experience with woodworkingo Seek outside advice and make detailed blueprints
Schedule• Split team into 3 groups
o Emulator, Boot Loader, and Cabinet
System Decomposition• FPGA
o CPUo PPUo Video outputo Controller Inputo Boot loader o Audio
• Cabineto Physical Controls
• Joystick• Buttons
o Monitor
System Design- Controls
• Develop an arcade style interface for the NES emulator
• Create wire riggings for all the joysticks and buttons
• Each button is mapped directly to the controller status register
System Design-Boot Loader
• Develop boot loader using Microblaze Processor provided in Xilinx tools
• Present user with easy to use game selection screen
• Read NES Rom files from Compact Flash
• Parse NES Rom file and load contents into appropriate system memory for the FPGA
• Reset back to boot loader screen when reset is pressed
System Design
System Design- Cabinet
• Use Solid Works to design detailed cabinet drawings
• Used feedback from client• Purchase custom marquees• Build out of ¾” plywood• Detachable Control Box• Hidden screw and nail holes• Hinged control box for easy viewing of
FPGA
System Design- Audio• Write audio module that generates
audio• Connect audio module to CPU• Map all audio related instructions from
the CPU to the module• Connect audio module to AC97 to
produce sound output
System Design• PPU
o Map CPU memory to PPU registers to allow for game scrolling
o Implement Memory mappers to allow for more games to be played
o PPU is implemented using a 14 stage finite state machine to render each pixel
o Each pixel is stored in a buffer that is then sent to the VGA output
Emulator Implementation
• Improved functionality of past group’s design
• Tweaked PPU and CPU clocks to more closely match the original NES
• Cleaned up existing code to make it more understandable for future projects
Emulator Testing• Tested modified pieces of
emulator separately• Ran tests found from
NES development community in ModelSim that tested the entire system completely
• When tests passed in ModelSim, implementation was tested for robustness on the hardware
CPU Timing Failure
Sprite Test Failure
Emulator Design Revision
• True NES hardware emulation required more resources then initially predicted
• Adopted strategy of software emulation• New design still met original goals of the project• Allows for over 120 games to work
Boot Loader Implementation
• C code written to run on PowerPC processor
• Initializes memories for screenshots, fonts, and music
• Program displays metadata from compact flash card
• Graphical interface allows user to select desired game from list
• Loads game data from ROM files into emulator memories
Boot Loader Testing• Tested boot loader
with debug statements sent through UART
• Debug statements used to verify values in memory, and functionality of software
Cabinet Construction• ¾” cabinet grade
plywood used for economical strength and durability
• Kreg Joints hide screws without compromising strength
• Used Jim Jensen as resource while building the cabinet
Cabinet Construction• Control box is removable from main cabinet
assembly for demonstrations on any VGA monitor• Wheels attached for easy transportation• Construction presented interesting engineering
challenges
Final CostsItem CostWheels $40.00Speakers $20.00Screws $10.00Plywood $90.00Marquee $20.00Marquee Light $20.00T-Molding $10.00Paint/Primer $50.00Monitor $500.00Cabinet Total $760.00
Labor – 1130hrs $22,600.00
Final Results
Moving Forward• Lessons Learned
o “Take the time to learn the tools”o “Allow for ample time to acquire supplies”o “Don't set goals until you understand the full complexity of the
project”o “Don't be worried about asking stupid questions”o “Have a base understanding before diving in”
• Future of the projecto Cabinet can be reusedo Networked gamingo Advanced systems
Questions