Transcript Design Review

Group 8: Video Game Console
Team Members:
Rich Capone
Hong Jin Cho
Dave Elliott
Ryan Gates
Project Overview
Purpose:
To create a simple video game system.
Functionality:
A “black box” with a controller input,
CompactFlash card interface, NTSC
video and single speaker sound output.
Project Overview
Project Success Criteria:
Ability to boot and initialize peripheral
devices
Ability to read data from CompactFlash
Ability to output NTSC video
Ability to interpret handheld controller
signal
Ability to generate sound to a system
speaker
SRAM
JTAG
Xilinx XC95108
RGB NTSC
Encoder
NTSC Composite
PWM
Sound Circuit
RS-232 &
BDM
Microprocessor
Motorola HCS12
Power Supply
5V
Compact Flash
(Game Cartridge)
Power/Reset
Button
SRAM
256K
Address
Latch
Game
Controller
Sound to
Speaker
Component Selection
Ram – CY7C109B
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Fast Access (12 ns)
2 x 128KB
Address Latches 74AHCT573
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8-bit Address Latch for Memory
Very Fast Address Latch (3.5ns)
Component Selection
Motorola HCS12
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Fast general I/O pins
Large number of I/O pins
Multiplexed data/address bus
25 Mhz
Development interface (CodeWarrior)
Via BDM and RS-232
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Simple RAM interface
Timings adjusted via registers
Component Selection
Xilinx XC95108
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Required number of pins (84pin PLCC)
In-circuit programmable
Development board available
Capable of 4x NTSC frequency
Preferred part from reference design
Component Selection
Voltage Regulator
Major ICs
Qty
Part #
Continuous
Current Req
Peak Current
Req
3
CY7C109
50
mA
1
MC9S12A256
65
mA
2
74VHC373/SO
75
mA
1
XC95108
<75
192.9
mA
1
MAX232
15
18
mA
1
AD724
33
42
mA
1
TC1034ECT
4
mA
Continuous IC Current Req.
~317mA
Peak IC Current Req.
~443.98 mA
Peak will add ~10% for
Capacitor charging.
Supply should be larger than necessary to prevent overdriving,
and for expansibility (additional handheld controllers, network
connectivity, etc)
Minimum regulator = 750mA Maximum regulator = 1.5A
Component Selection
Voltage Regulator
Solutions:
MAX 744A
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1A load current
LM1572
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1.5A load current
LM1572 is the current design choice however, if less current is
required, the MAX744A can be used to increase efficiency.
CompactFlash
Parts Necessary for Packaging
SPDT Power/
SPST Reset switch
Wall wart
RCA jack
Nintendo NES Controller
AutoCAD design of Game System – 3D Front
AutoCAD design of Game System – 3D Back
CompactFlash Adaptor
AutoCAD design of Game System - Front
2 port RCA Jack
AutoCAD design of Game System -Back
AutoCAD design of Game System - Left
Schematic Overview
Schematic – Power Supply
The Power Supply is a basic switching regulator.
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Two reference designs are under consideration, a
final choice will be based upon a final circuit mock-up
to determine actual current draw.
The circuit board will utilize a unique jumper based
voltage isolation scheme. The board will have the
ability to turn on/off +5V to both the video circuit, and
the main microcontroller circuit to aid in debugging as
well as isolate chips to simplify programming. Noise
introduction will be minimal compared to utility in
debugging.
Schematic – Motorola
Available Ports (all ports are 8bit):
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Port A – Address [15:8] Data Bus [0:7] (multiplexed)
Port B – Address [0:7]
(multiplexed)
Port K -- Extended Addressing
Port W – Main RAM Control Signals
Port H – Video Ram Control Signals
Port J – CF Address bus
Port M – CF Data bus
Port T – CF Control signals – Controller Data
Port P (PWMs) – Audio[0] – Handheld controller[1:2]
Port S
– RS-232 (Serial Comms)
Port A/D
-- A/D Converters (not used)
Schematic – Motorola
Programming accomplished via the BDM
interface (Background Debug Mode).
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Pin BKGD
Processor Core voltage generated by onchip step-down voltage regulator. 5V-3.3V
Schematic – Motorola Crystal
Capacitors for the crystal
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Typical input capacitance : 9 nF
Citizen 16 Mhz crystal has 18 nF
capacitance.
Input capacitance: 31.9 nF
Phase Locked Loop Filter
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R < 4606 ohm
Cs > 5.9 nF
Cs/20 <= Cp <= Cs/10
Cs = 22 nF, Cp = 2.2 nF, Rs = 1Kohm
Meets the spec!
Schematic – Data/Address Bus
Schematic – Video System
Xilinx CPLD updates Video RAM, drives
the NTSC encoder and interfaces to
memory
Resistor matrix creates analog RGB
signals
Video RAM stores the screen image (4
bits per pixel)
AD724 converts analog RGB signals into
NTSC video
Schematic - CompactFlash
Memory mode – Byte by Byte access
8bit data, 3bit address pins
Over current protection
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220uF bulk capacitor
Operation
Address register setup
Command
register setup
Buffer filled with a sector
data
Strobing CFOE low accesses next
byte from the buffer.
Writing is similar, except using CFWE
instead of CFOE.
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Schematic -- RS-232
The HCS12 has a built-in RS-232 port.
That will be connected to a MAX232 line
driver for isolation.
This port will mainly be used for debugging
and interfacing to Motorola’s CodeWarrior
suite.
Digital Audio
The audio circuit is a PWM driven follower
circuit.
1 channel means simplistic audio where
the audible frequency (tone) is adjusted by
the PWM duty cycle.
Audio is not a critical goal of the design, so
simple beeps [and boops] will suffice.
Questions??