Microelectronic Systems--University of Tennessee 1 1 Music Synthesizer Design Christopher Boyd Ki Shin Electrical & Computer Engineering University of Tennessee Knoxville, TN

Microelectronic Systems--University of Tennessee 2 2 OUTLINE Design Requirements –Board Design Overview –Module Hierarchy –Note Signal »Pitch –Synthesizer Pre-Synthesis Simulation Post-Synthesis Simulation Conclusion

Microelectronic Systems--University of Tennessee 3 3 Design Requirements RequirementsRealized Functions Play Music from Stored Music File, with the ability to switch between the four octaves. (1)Memory Controller for Read/Write (Proposal)  Used VHDL Sub Module for Sheet Music (Final) (2) Music Synthesizer  Able to make stereo sounds from Sheet Music (3) Synthesize four different octaves  Able to achieve 4 octave harmony (4) Button control for changing octave (Proposal)  Used Switches to make Synchronization (Final)

Microelectronic Systems--University of Tennessee 4 4 Spartan-3A Board We decided to use the Spartan-3A, since it had a 3.5 mm jack for music output.

Microelectronic Systems--University of Tennessee 5 5 Spartan-3A (Xilinx ISE)

Microelectronic Systems--University of Tennessee 6 6 Spartan-3A (FPGA Editor)

Microelectronic Systems--University of Tennessee 7 7 X200 Synthesis (ISE)

Microelectronic Systems--University of Tennessee 8 8 Altera Cyclone II (Quartus)

Microelectronic Systems--University of Tennessee 9 9 Mentor Graphics Block Diagram

Microelectronic Systems--University of Tennessee 10 Design Overview with I/O Block Block Diagram Synthesizer Specify File (Controller) Specify File (Controller) Speaker (Left) Change Scale Switch (0~3) Sheet Music (Sub Module) Sheet Music (Sub Module) Christopher Boyd Ki Shin Speaker (Right)

Microelectronic Systems--University of Tennessee 11 Hierarchy of Modules Music.vhd (Main Controller + Music Synthesizer) Music.vhd (Main Controller + Music Synthesizer) Music 3 : Jingle Bell (Melody Tone) Music 3 : Jingle Bell (Melody Tone) Music 2 : Amazing Grace (Melody Tone) Music 2 : Amazing Grace (Melody Tone) Music 1 : Rocky Top Music 1 : Rocky Top Music 3_1 : Jingle Bell (Base Tone) Music 3_1 : Jingle Bell (Base Tone) Music 2_1 : Amazing Grace (Base Tone) Music 2_1 : Amazing Grace (Base Tone)

Microelectronic Systems--University of Tennessee 12 Explanation of Note Signal Signal (Note) – 8 bits 4 bits  16 states : Assign Note Scale (C, C#, D, …. ) 1 bit  2 states : Assign High Tone 3 bit  8 states : Assign Duration (Whole / Half … ) If Note = “ ”, that means EOF (End of File)

Microelectronic Systems--University of Tennessee 13 Pitch of Notes

Microelectronic Systems--University of Tennessee 14 Synthesizer 50 MHz Clock Clock Divider Music file Note Signal Switch Input Octave Toggle 1/0 Left Speaker Left Speaker Right Speaker Right Speaker

Microelectronic Systems--University of Tennessee 15 Pre – Synthesis Simulation By Swt input, music is changed Out By Octave input, frequency is changed Out Freq. Out Freq.

Microelectronic Systems--University of Tennessee 16 Post – Synthesis Simulation By Swt input, music is changed By Octave input, frequency is changed

Microelectronic Systems--University of Tennessee 17 Issues Encountered Since the signal sent to the speakers is digital (0 or 1) rather than analog, we couldn’t output more than one tone (per speaker) at once. Attempting to half the volume didn’t work either. (by sending 1010 instead of 1111) –Being able to vary the volume would have been useful for reverb as well as multiple tones.

Microelectronic Systems--University of Tennessee 18 CONCLUSIONS We were limited by the hardware we had on hand. –Can play, at most, two tones at once with stereo sound. Parallel Processing –We could play different music at the same time and select the file by using switches. –For parallel processing, synchronization is very important. Synchronization issues –When changing songs, the two parts could desync. –We fixed this by resetting the note being played, when we change songs.

Microelectronic Systems--University of Tennessee 19 Appendix – Rocky Top