Aztec PC Oscilloscope

Michael MasonJed BrownJosh PriceAndrew 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.

Scope

S C

A/DSpartan-3

SDRAM

M C

USBControlle

r

eeprom

Serial

PC

Block Diagram

USB ControllerUM232R 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 KitConnectors 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

4-digit 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

MicrocontrollerSiemens 805116-bit addressable, 8-bit data, 64kB accessible external RAMBasic 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 ListPart Quantity Part QuantityTrimCap 1 Perf Board 147 pF Capacitor 2 Power Supply 1300 Ohm Resistor 1 MAX233 (233) 11M Ohm Resistor 1 LM7805 - Voltage Reulator 125 Ohm Resistor 4 MX7821 - ADC 2196 Ohm Resistor 8 Seimens C501 Microcontroller 2392 Ohm Resistor 5 LS7408 - AND Gate 2600 Ohm Resistor 4 74LS156 - Decoder 11k Resistor 4 74LS373 - Latch 1100 Ohm Resistor 12 77C256 - EPROM 1ADS807E 1 62256 - SRAM 1MAX4545 Quad Switches 4 Crystal Oscillator 1THS4215 Opamp 4 Misc Microcontroller PartsCLC5526 Variable Gain Amplifier 1SN54HC541 Tri State Buffer 2UM232R - USB - Serial UART 1EVAL232R - a USB - RS232 converter 1ADS826E  - ADC 3SN74HC541NSRG4 - ADC 3THS1040IPW - ADC 3PCB-SSOP-20 : SSOP to DIP Adapter 20-Pin 4PCB-SOIC-20 : SOIC to DIP Adapter 20-Pin 5

Updated Schedule

Timeline – Milestone 1Micro controller

Programming Complete Serial Interface Working

A/D Converter 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 Sending signals to micro controller Updated graphing capabilities

PCB 2nd revision submitted and tested.

A/D connection to FPGA Data being received and stored

Division of LaborMike

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 ? ? ?