Functional Blocks and FMECA Chart Daryl Sielaff Ben

Functional Blocks and FMECA Chart Daryl Sielaff Ben Mc. Quiston Will Mc. Kenna David Hartman

Schematic Block A: Power

FMECA Chart Failu re No. A 1 Failure Mode Output = 0 V Possible Causes Failure Effects Short to ground or any component in A Audio Amp fails to work, LCD fails to operate properly, short could lead to overheating Failure of 5 V regulator Could damage audio amplifier or LCD A 2 Output > 5 V Method of Detection Observation Criticality High Failure of 3. 3 V regulator Could damage m. C or data bus Observation Low Regulators have shut off if voltage reaches unsafe values A 4 A 5 Overheating could cause fire or sparks Regulators have shut off if voltage reaches unsafe values A 3 Output > 3. 3 V Remarks Output > 1. 2 V Failure of 1. 2 V regulator Potential damage to m. C core Observation Low Output of Tolerance Failure of any of the bypass capacitors Logic levels not properly achieved Observation Low

Schematic Block B: USB

FMECA Chart Failure No. Failure Mode Possible Causes Failure Effects USB drive not recognized Any part of the USB module fails, software Cannot complete file conversions or access existing IMS or MIIDI files Observation Low Nothing of significance happens if the USB is not recognized Unable to write to USB drive Failure of external memory, data bus, or software Cannot store IMS or MIDI files back onto USB drive Observation Low Still able to actually hear audible music B 1 B 2 Method of Detection Criticality Remarks

Schematic Block C: Micro

FMECA Chart Failure No. Failure Mode Possible Causes Failure Effects Method of Detection Criticali ty Continual Output of logic low Failure of m. C, or any components associated with it Data bus no longer providing reliable data, LCD output unpredictable Observation Low Continual output of logic high Failure of m. C or any components associated with it Unreliable data bus, LCD output unpredictable Observation Low Image file not processed correctly Software, failure of data bus transmission If IMS created, not valid with matching image IMS file improperly converted to MIDI Software, failure of data bus transmission MIDI will not match image C 1 C 2 C 3 C 4 Observation Remarks Low Music played will not match sheet music

Schematic Block D: External Memory

Schematic Block E: Audio Chip

FMECA Chart D 1 Data not properly stored or accessed in/from external memory Timing failure, bus fighting, Cannot access IMS for conversion or MIDI for playback Accessing incorrect chips for given instructions Failure of chip select PLD Bus fighting, cannot do anything significant with any chip No audio out Any part of audio block Low Unpredictable results in this failure case Observation Low Nothing significant can be produced in this situation Unable to hear desired music Observation Low Distorted or noisy audio out Noisy power signal, speaker damage, failure of audio amp Unable to interpret desired music Observation Low Uncontrollably loud output Unpredictable audio amplifier behavior Harm to user, unable to hear music Observation High D 2 E 1 E 2 E 3 Observation Hearing loss possible

Schematic Block F: LCD F F

FMECA Chart F 1 LCD not functioning properly Failure of any connections to m. C, software Backlight off or too bright, no way to navigate menu Observation High F 2 Pushbuttons or RPG have no effect Failure of connections to m. C, software Cannot navigate menu Observation Low LCD backlight could overheat and lead to burns