Github: https://github.com/ultraembedded/minispartan6-audio
An audio player (MP3) based on the Scarab Hardware miniSpartan6+ FPGA board featuring my RISC-V CPU, SDRAM controller and peripherals.
# Clone repository and submodules
git clone https://github.com/ultraembedded/minispartan6-audio.git --recursive
- 50MHz RISC-V (RV32IM) CPU with ICACHE (2-way x 8KB), DCACHE (2-way x 8KB write-back).
- AXI4 infrastructure.
- SDRAM controller.
- SPI (SD card) interface.
- 2-ch audio controller (sigma delta DAC).
- UART -> AXI debug bridge (for loading code, etc).
I originally created a FPGA soft-CPU based MP3 player around a MIPS derivative in 2012 (Hackaday)
This time, I've rebuilt it around my RISC-V (RV32IM) CPU, SDRAM controller and SoC peripherals;
| Component | Description |
|---|---|
| audio | Audio Controller and FIFO |
| core_soc | SoC peripherals (timer, SPI, GPIO, UART) |
| dbg_bridge | UART -> AXI debug bridge |
| riscv | RISC-V (RV32IM) |
| sdram | AXI4 SDRAM Controller |
The application code will play any MP3s found in the root directory of a FAT32 formatted SD card placed in the microSD card slot of the FPGA dev board.
Design Summary
--------------
Design Summary:
Number of errors: 0
Number of warnings: 10
Slice Logic Utilization:
Number of Slice Registers: 2,681 out of 11,440 23%
Number used as Flip Flops: 2,681
Number used as Latches: 0
Number used as Latch-thrus: 0
Number used as AND/OR logics: 0
Number of Slice LUTs: 5,652 out of 5,720 98%
Number used as logic: 5,072 out of 5,720 88%
Number using O6 output only: 3,889
Number using O5 output only: 279
Number using O5 and O6: 904
Number used as ROM: 0
Number used as Memory: 519 out of 1,440 36%
Number used as Dual Port RAM: 518
Number using O6 output only: 70
Number using O5 output only: 14
Number using O5 and O6: 434
Number used as Single Port RAM: 0
Number used as Shift Register: 1
Number using O6 output only: 1
Number using O5 output only: 0
Number using O5 and O6: 0
Number used exclusively as route-thrus: 61
Number with same-slice register load: 47
Number with same-slice carry load: 14
Number with other load: 0
Slice Logic Distribution:
Number of occupied Slices: 1,430 out of 1,430 100%
Number of MUXCYs used: 1,300 out of 2,860 45%
Number of LUT Flip Flop pairs used: 5,701
Number with an unused Flip Flop: 3,190 out of 5,701 55%
Number with an unused LUT: 49 out of 5,701 1%
Number of fully used LUT-FF pairs: 2,462 out of 5,701 43%
Number of unique control sets: 215
Number of slice register sites lost
to control set restrictions: 854 out of 11,440 7%
A LUT Flip Flop pair for this architecture represents one LUT paired with
one Flip Flop within a slice. A control set is a unique combination of
clock, reset, set, and enable signals for a registered element.
The Slice Logic Distribution report is not meaningful if the design is
over-mapped for a non-slice resource or if Placement fails.
IO Utilization:
Number of bonded IOBs: 61 out of 186 32%
Number of LOCed IOBs: 61 out of 61 100%
IOB Flip Flops: 61
Specific Feature Utilization:
Number of RAMB16BWERs: 22 out of 32 68%
Number of RAMB8BWERs: 2 out of 64 3%
Number of BUFIO2/BUFIO2_2CLKs: 1 out of 32 3%
Number used as BUFIO2s: 1
Number used as BUFIO2_2CLKs: 0
Number of BUFIO2FB/BUFIO2FB_2CLKs: 0 out of 32 0%
Number of BUFG/BUFGMUXs: 1 out of 16 6%
Number used as BUFGs: 1
Number used as BUFGMUX: 0
Number of DCM/DCM_CLKGENs: 0 out of 4 0%
Number of ILOGIC2/ISERDES2s: 17 out of 200 8%
Number used as ILOGIC2s: 17
Number used as ISERDES2s: 0
Number of IODELAY2/IODRP2/IODRP2_MCBs: 0 out of 200 0%
Number of OLOGIC2/OSERDES2s: 44 out of 200 22%
Number used as OLOGIC2s: 44
Number used as OSERDES2s: 0
Number of BSCANs: 0 out of 4 0%
Number of BUFHs: 0 out of 128 0%
Number of BUFPLLs: 0 out of 8 0%
Number of BUFPLL_MCBs: 0 out of 4 0%
Number of DSP48A1s: 4 out of 16 25%
Number of ICAPs: 0 out of 1 0%
Number of MCBs: 0 out of 2 0%
Number of PCILOGICSEs: 0 out of 2 0%
Number of PLL_ADVs: 1 out of 2 50%
Number of PMVs: 0 out of 1 0%
Number of STARTUPs: 0 out of 1 0%
Number of SUSPEND_SYNCs: 0 out of 1 0%
To build the firmware, make sure the RISC-V GCC (built for RV32IM) are in the PATH, then type:
# Add RISC-V GCC to path
export PATH=$PATH:/opt/riscv32im/bin/
# Build firmware
make
The FPGA board has a FTDI dual channel FT2232H where channel A (usually /dev/ttyUSB1) is used for loading the bitstream, and channel B (usually /dev/ttyUSB2) is used for a virtual serial port.
The tools provided for loading the firmware need to be pointed at channel B, e.g;
make run TARGET_PORT=/dev/ttyUSB2
ELF: Loading 0x80000000 - size 79KB
|XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX| 100.0%
SD Test
Directory /
01 Kaiser Chiefs - Ruby.mp3 [3284992 bytes]
02 Kaiser Chiefs - The Angry Mob.mp3 [4616192 bytes]
03 Kaiser Chiefs - Heat Dies Down.mp3 [3796992 bytes]
04 Kaiser Chiefs - Highroyds.mp3 [3196928 bytes]
05 Kaiser Chiefs - Love's Not A Competition [But I'm Winning].mp3 [3168256 bytes]
06 Kaiser Chiefs - Thank You Very Much.mp3 [2527232 bytes]
07 Kaiser Chiefs - I Can Do Without You.mp3 [3270656 bytes]
08 Kaiser Chiefs - My Kind Of Guy.mp3 [3948544 bytes]
09 Kaiser Chiefs - Everything Is Average Nowadays.mp3 [2639872 bytes]
10 Kaiser Chiefs - Boxing Champ.mp3 [1460224 bytes]
11 Kaiser Chiefs - Learnt My Lesson Well.mp3 [3762176 bytes]
12 Kaiser Chiefs - Try Your Best.mp3 [3563520 bytes]
13 Kaiser Chiefs - Retirement.mp3 [3739648 bytes]
01 The Chemical Brothers - No Path To Follow.mp3 [1523295 bytes]
02 The Chemical Brothers - We Are The Night.mp3 [9431501 bytes]
03 The Chemical Brothers - All Rights Reversed.mp3 [6775161 bytes]
04 The Chemical Brothers - Saturate.mp3 [6929388 bytes]
05 The Chemical Brothers - Do It Again.mp3 [7997065 bytes]
06 The Chemical Brothers - Das Spiegel.mp3 [8390156 bytes]
07 The Chemical Brothers - The Salmon Dance.mp3 [5248565 bytes]
08 The Chemical Brothers - Burst Generator.mp3 [9914244 bytes]
09 The Chemical Brothers - A Modern Midnight Conversation.mp3 [8560056 bytes]
10 The Chemical Brothers - Battle Scars.mp3 [8417114 bytes]
11 The Chemical Brothers - Harpoons.mp3 [3482479 bytes]
12 The Chemical Brothers - The Pills Won't Help You Now.mp3 [9438397 bytes]
Playing '/01 Kaiser Chiefs - Ruby.mp3'..
The python firmware loader tools require access to the serial port (user permissions), python-serial and ELF libraries;
# Pip install of required python libraries
pip install pyserial --upgrade
pip install pyelftools --upgrade
# (or) Ubuntu/Debian/Mint python libraries install
sudo apt-get install python-serial python-pyelftools