Team 2 Yimin Xiao Jintao Zhang Bo Yuan Yang

 The project we propose is a digital oscilloscope with playback function that provides almost any function of a typical oscilloscope, such as digital sampling, signal processing, auto-scale setting, cursor setting, reconstruction and visualization of signals. Additional features such as recording and replicating signals as a function generator, interacting with PC via USB and GUI display of signals will also be included.

 An ability to sample analog V/I signal via BNC  An ability to reconstruct and display the sampled signal on VGA display  An ability to create general oscilloscope interface and realize basic functions  An ability to store/load the sampled signal to/from external memory  An ability to replay signal stored in external storage device

 Critical Conditions  Major components for analysis  Failure mode, effects, and criticality analysis (FMECA)

 Power circuit Overload ◦ Linear regulator failure  Overload of input voltage (Harm to product only) ◦ User select wrong voltage input scale ◦ Multiplexer did not work correctly ◦ Zener diode failure  Input not acknowledged (Harm to product) ◦ Amplifier overloaded ◦ ATD channel failure

Xilinx Spartan-3E ℷ p = 3.99 MTTF: ~ 28.6years STM32 MCU ℷ p = MTTF: ~ 17 years

Linear Regulator ℷ p = 0.48 MTTF: ~ 238 years Zener Diode ℷ p = MTTF: ~ 891 years

Analog MUX ℷ p = MTTF: ~ 722 years Instrumentation amplifier ℷ p = * * Calculated by combination of internal/ external components.

 A – Inputs, include circuitry and analog voltage  B – Power circuitry  C – FPGA, display unit  D – MCU, sampling process (digital value)  E – Transmission

Failure No.Failure Mode Possible Causes Failure Effects Detection Method Criticalit y A1 (MUX, Zener) Input mode error Wrong selection, MUX failure Overload INA, ATD or resistor Output Error. (or smell?) High A2 (STM32, INA) Input not received ADC channel/ INA118 No detectable output Output Error. Low B1 (ATX power, Regulator) Power overloaded Regulator failure, overheat Component damage Extreme hot parts High C1 (FPGA, VGA display) No output to screen Wrong FPGA code, /VGA mode No displayObserveLow

Failure No.Failure ModePossible Causes Failure Effects Detection Method Criticality D1 (STM32) Wrong data sampled Code bug, wrong ADC mode Wrong samples Compare input and sample Low D2 (STM32) Wrong value calculation FFT algorithm error Display error values for user observeLow D3 (STM32, pushbutto n) RPG/ Pushbutton not detected Pushbutton/RP G pull up circuit failure, input sample failure No response to user control observeLow E1 (STM, FPGA) I2C transmission error, EM interference Wrong data transmitted Wrong display data received Debug via certain packet High