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Kanto: FPGA Audio Player and Visualizer Kavita Jain-Cocks Zhehao - - PowerPoint PPT Presentation
Kanto: FPGA Audio Player and Visualizer Kavita Jain-Cocks Zhehao - - PowerPoint PPT Presentation
Kanto: FPGA Audio Player and Visualizer Kavita Jain-Cocks Zhehao Mao Amrita Mazumdar Darien Nurse Jonathan Yu May 16, 2013 Project Overview Objective: Design and implement an audio player with frequency visualization. Hardware:
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High-Level Overview
NIOS II VGA Display Avalon Visualizer FFT SD Card Controller Audio Buffer Speaker Output PLL Conductor SD Card SD Buffer everywhere PS2 Keyboard
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SD Controller
CMD0 CMD8 illegal? Error ACMD41 ready? CMD58 Ready CMD17 no yes yes no start? yes no
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Audio Buffer
Audio RAM WM8731 Interface From SD Card To Audio Codec
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FFT Equations
Xk =
N−1
- n=0
xne− 2πj
N nk
(1) Xk =
- Ek + e− 2πj
N kOk
if k < N/2 Ek−N/2 − e− 2πj
N (k−N/2)Ok−N/2
if k ≥ N/2. (2)
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FFT Top-Level
DFT DFT Recomb Time Domain RAM MUX MUX Frequency Domain RAM Controller Recomb ROM-32 Recomb ROM-64 Recomb ROM-128 Recomb ROM-16 MUX DFT ROM
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DFT Unit
- u
t p u t n +1 ROM x x + +
Sum
k +1 F S M c
- n
t r
- l
l e r i n p u t
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Recombination Unit
ROM +1 Complex Add Complex Subtract N write addr low high Frequency Domain RAM = FSM k write done Complex Mult even
- dd
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Complex Multiplier
ax bx ay by x x x x
ax * ay bx * by ay * bx
- +
ax * by
az bz
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Visualizer
data 31:0 clk_50 clk_25 red green blue data_req_addr reset_data FSM Data Array of size 16 19:0 Draw to VGA
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Conductor
initial cpuctrl trigger_sd wait_sd resume playing fft_end block_end sd_ready = 1 / fft_counter <= 11 nios_play = 1 / blockaddr++ nios_readblock = 1 / blockaddr <= nios_addr sd_ready = 1 / ~ nios_play = 0 / ~ ab_swapped = 1 / fft_counter++ blockaddr++ fft_done_last = 0 fft_done = 1 / ~ ~ / fft_counter <= 00 ~ / ~ ~ / ~ ~ / ~
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Software — Track Selection
Track 1 Address Track 1 Title track_table[0] track_titles[0] track_table[1] track_titles[1] Track 1 Address Track 1 Title Audio End track_table[N]
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The Hard Parts
◮ Interfacing to external hardware (SD card, audio codec,
visualizer)
◮ Reducing Hardware Usage ◮ Timing Issues
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Design Changes
◮ Removal of SRAM ◮ Adding Software Control ◮ Display Changes
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