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Aztec PC Oscilloscope
Michael Mason
Jed Brown
Josh Price
Andrew Youngs
Changes in Design since PRD
Spartan 3 Starter kit replaces Spartan 3E Kit
Reason: Cheaper and more readily available.
Better alternative for low-income students. Not
hard to tweak code for the 3E.
Siemens 8051
 Reason: Already known by us, provides enough.
PC Communication Serial and USB
 Initially PC->Scope communication will be via
serial cable to the uC.
 Scope Data -> PC will de via serial/USB interface
from the FPGA.

Block Diagram
Scope
SC
A/D
S
D
R
A
M
Spartan-3
eeprom
MC
Serial
PC
USB
Controller
USB Controller
UM232R
UART Interface supports 7/8 bit data, 1/2 stop
bits, and Odd/Even/Mark/Space/No Parity
Transfer Data Rate 300k to 1Mega Baud (RS232)
FIFO receive and transmit buffers
for high data throughput.
Integrated 3.3V level converter
for USB I/O.
Spartan-3 FPGA Board
Xilinx Devices:

Spartan-3 (XC3S200)
Clocks: 50 MHz crystal clock oscillator
Memory

256Kx16 ISSI - 10 ns SRAM devices
Spartan-3 Starter Kit
Connectors and Interfaces








Xilinx Spartan-3 FPGA w/ twelve 18-bit multipliers,
216Kbits of block RAM, and up to 500MHz internal
clock speeds
-200, -400, and -1000 versions available
On-board 2Mbit Platform Flash (XCF02S)
8 slide switches, 4 pushbuttons, 9 LEDs, and 4digit seven-segment display
Serial port, VGA port, and PS/2 mouse/keyboard
port
Three 40-pin expansion connectors
Three high-current voltage regulators (3.3V, 2.5V,
and 1.2V)
1Mbyte on-board 10ns SRAM (256Kb x 32)
Spartan-3 Schematic
Expansion Slot Schematic
Microcontroller
Siemens 8051
16-bit addressable, 8-bit data, 64kB
accessible external RAM
Basic control unit for enables, external
peripherals (SPI with ADC)
Will interface with the computer for
sending data and receiving user
commands (RS-232).
Microcontroller
Voltage Regulator
Latch, Decoder, EPROM, and
SRAM from uC
(32kx8 EPROM for program memory)
(32kx8 SRAM for external memory)
EEPROM from uC
(16kbit serial)
Serial Port
Serial Peripheral Interfacing
(SPI)
•SCK (Serial Data Clock): Data is shifted/latched on the
rising or falling edge of SCK (see next section).
•MOSI (Master Output/Slave Input): Data is transmitted
out of this pin if the chip is a Master and into this pin if the
chip is a Slave.
•CS (Chip Select, active low): Tells the peripheral that a
transfer is about to begin.
Analog to Digital Conversion
 Differential Input
 ADC: 3V peak to peak maximum input
 Voltage Reference
Input Stage
Capacitive
Impedance
matching
1:1, 10:1
Attenuation
AC Coupling
Single-Ended to Differential
Stage
Feedback Control
4 Gain Levels: 2, 4, 6, 10
Gain Stage #2
CLC5526: Digitally Controlled Variable
Gain Amplifier
+30 dB to –12dB
ADS807
Internal Reference Voltage
Input: 3Vpp (V+ - V- <3V)
Clock Input from FPGA:
10k to 53M samples/sec
12-bit Output Buffered, sent
to FPGA
Software – FPGA
Labview Module using VESA interface.
Communication via virtual COM port
drivers.


Cause the USB device to appear as an
addition com port available to the PC.
Applications can access the USB device in
the same way as it would access a
standard COM port.
Software – User GUI
Initial development in both MATLAB and
Labview


Labview has better interface modules but
more difficult to program the GUI.
MATLAB is easier to program the GUI but
the advanced controls will be more difficult
Use Labview to develop GUI with
MATLAB as a fallback.
Graphical User Interface
Inputs


Data will be inputted via USB from the
FPGA board.
Data Format
 8 bit data transfer
 1 stop bit
 0 parity bits

Data speeds will be 300k – 1M baud
Graphical User Interface cont.
Outputs

Serial output to Microcontroller
 Data will be 8 bit with 1 stop bit. (RS232)

Graphical Output to Monitor
 Data Graphs
 Controls to manipulate data graph and perform
analysis.
 Control inputs to be sent to micro controller.
Parts List
Part
Quantity
Part
Quantity
TrimCap
47 pF Capacitor
300 Ohm Resistor
1M Ohm Resistor
25 Ohm Resistor
196 Ohm Resistor
392 Ohm Resistor
600 Ohm Resistor
1k Resistor
100 Ohm Resistor
ADS807E
MAX4545 Quad Switches
THS4215 Opamp
CLC5526 Variable Gain Amplifier
SN54HC541 Tri State Buffer
UM232R - USB - Serial UART
EVAL232R - a USB - RS232 converter
ADS826E - ADC
SN74HC541NSRG4 - ADC
THS1040IPW - ADC
PCB-SSOP-20 : SSOP to DIP Adapter 20-Pin
PCB-SOIC-20 : SOIC to DIP Adapter 20-Pin
1
2
1
1
4
8
5
4
4
12
1
4
4
1
2
1
1
3
3
3
4
5
Perf Board
Power Supply
MAX233 (233)
LM7805 - Voltage Reulator
MX7821 - ADC
Seimens C501 Microcontroller
LS7408 - AND Gate
74LS156 - Decoder
74LS373 - Latch
77C256 - EPROM
62256 - SRAM
Crystal Oscillator
Misc Microcontroller Parts
1
1
1
1
2
2
2
1
1
1
1
1
Updated Schedule
Timeline – Milestone 1
Micro controller
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Programming Complete
Serial Interface Working
A/D Converter
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Circuit design complete
Prototype complete and tested
FPGA


Programming mostly complete
USB interface started
Software

GUI preliminary programming, simple I/O
PCB

Schematics completed for 1st revision.
Timeline – Milestone 2
FPGA


Programming complete
Trigger mode enabled
Software

GUI updated to include all necessary functionality.
PCB 2


2nd Revision submitted and received.
Make sure PCB is working
A/D

Filtering implemented as necessary
Timeline – Expo
Scope Working


All parts integrated
PCB completely tested and connected to FPGA
board.
Extras

GUI interface updated as time allows
Documentation Completed
USB interface working

Data transmitting from FPGA to PC
GUI
Division of Labor
Mike
 Software – GUI Interface, FPGA Programming
 USB Interface
 Assist Josh with microcontroller and Drew with A/D
Jed
 FPGA Programming
 Software Interface
 Assist with A/D converter
Drew
 A/D converter
 Microcontroller Interface
 FPGA Interface
Josh
 Microcontroller
 Interface with A/D converter
 Serial Interface with Computer
Questions ? ? ?