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I'm Fomu

Fitting an FPGA in your USB port...

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Download toolchain!

Step 1

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Tim

"mithro"

Ansell

I'm the "manager"

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Michael

"many hats"

Gielda

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Sean

"xobs"

Cross

I do the work

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Tomu FPGA

Lattice iCE40UP5K
5k LUTs + DSP tiles
128kb^ RAM
2064kb^ Flash (QIO, XIP)

1 x RGB LED
2 x ~touch buttons�
Fits inside your USB port

^kilobytes

I'm Tomu

Send pull request →

get hardware!

An MCU inside a USB port

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Download toolchain!

Step 1

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Assembly Fomu

Step 2

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Awesome Plastic Case

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Awesome Plastic Case

Open source
FreeCAD models
STEP files

case
tool

Same mold base

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Download toolchain!

Step 1

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Assembly Fomu

Step 2

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Do workshop!

workshop.fomu.im

Step 3

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An Introduction

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Python in your USB Port

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Tomu FPGA

fupy.github.io

FPGA µPython

I'm Tomu

Send pull request →

get hardware!

An MCU inside a USB port

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Circuit Python

I'm Tomu

Send pull request →

get hardware!

An MCU inside a USB port

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RISC-V in your USB Port

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Tomu FPGA

Lattice iCE40UP5K
5k LUTs + DSP tiles
128kb^ RAM
2064kb^ Flash (QIO, XIP)

1 x RGB LED
2 x ~touch buttons�
Fits inside your USB port

^kilobytes

I'm Tomu

Send pull request →

get hardware!

An MCU inside a USB port

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Tomu FPGA

Tools

Could use it just as �

Development toolchain;

(upstream) GCC
Bare Metal C
Zephyr RTOS
(maybe?) UF2 + DFU

CPU!

I'm Tomu

Send pull request →

get hardware!

An MCU inside a USB port

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RISC-V - VexRiscv

Several designs to choose from
Compilers are upstream
Embeddable on an ICE40UP5K
On-chip Debugger Support

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Debugging through USB

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Debugging through USB

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GDB over USB

[Run gdb over Wishbone over USB]

$ riscv64-unknown-elf-gdb riscv-blink.elf -ex 'target remote localhost:1234'

GNU gdb (GDB) 8.2.90.20190228-git

...

Reading symbols from .\riscv-blink.elf...

Remote debugging using localhost:1234

csr_writel (addr=3758106660, value=1) at ./include/hw/common.h:41

41 *((volatile uint32_t *)addr) = value;

(gdb) bt

#0 0x2004014c in csr_readl (addr=3758106664) at ./include/hw/common.h:46

#1 timer0_value_read () at ./include/generated/csr.h:242

#2 0x200401dc in msleep (ms=ms@entry=80) at ./include/hw/common.h:41

#3 0x20040074 in main () at ./src/main.c:45

(gdb)

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FPGA in your USB Port

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Tomu FPGA

Tools

Fully

open source

toolchain

�Verilog → Bitstream

Lattice iCE40UP5K

I'm Tomu

Send pull request →

get hardware!

An MCU inside a USB port

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Open source tools

Compiler - gcc
Synthesizer - yosys
Place-and-Route - nextpnr
Packing - icestorm
Bootloader - dfu-utils
Interaction - wishbone-tool

Simple installation: just set PATH

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Migen - Write Python hardware

Outputs Verilog

Great for simulation!
Helps understand what's�going on inside migen

Native finite state�machine support
Multiple clock domains
No distinction between�"reg" and "wire"

transfer = FSM(reset_state="WAIT_TOKEN")

self.submodules.transfer = transfer

transfer.act("ERROR",

self.error.eq(1),

If(self.reset, NextState("WAIT_TOKEN"))

)

transfer.act("WAIT_TOKEN",

If(rx.o_pkt_start, NextState("RECV_TOKEN"))

)

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Emulating the Fomu in your USB Port...

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Renode

Support for whole SoCs

RISC-V,
Cortex-A,
Cortex-M, and
other stuff�

Platforms are modular and text-based, tweak as you like
Same binary runs in Renode and on HW
Use for development/debugging and Continuous Integration

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Renode Fomu Support!

Simulation of VexRiscv
Simulation of many LiteX peripherals
Working on ValentyUSB simulation�
Therefore Fomu configs can be simulated in Renode!
Ships with an example Fomu config!

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Renode + Fomu via bridge

Simulate part in Renode, part on Fomu
Communicates over USB-Wishbone bridge

Gives you;

precise HW behavior in FPGA, and
Renode debugging/testing capabilities

Example;� - Control an LED on Fomu� - Step-by-step tutorial

USB

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Renode + Fomu via bridge

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The Tomu family!

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Tomu

Tim's Open Micro USB

j.mp/tomu-cs

ARM Cortex M0+
8k RAM, 64k Flash
Build yourself!

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Fomu

Fpga Tomu

iCE40UP5K FPGA
128kb RAM, 2mb Flash
Configurable hardware!

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Somu

Security Tomu

j.mp/somu-cs

Arm Cortex M4
64kb RAM, 256kb Flash
STM32L432KC "Secure Processor"
Security Key!

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Femu

The Femto ESP32 Tomu

j.mp/femu-had

ESP32-D2WD
512kb RAM, 448kb Flash
Under current development...
Wifi + Bluetooth!

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Femu

Wireless Tomu

j.mp/femu-had

ESP32-D2WD
512kb RAM, 448kb Flash
Uses FTDI, needs soft USB stack!
Wifi + Bluetooth!

Womu

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Bomu

Bluetooth Tomu

Doesn't exist yet...

Arm Cortex M4
256kb RAM, 1mb Flash
nRF52840 "Secure Processor"
Security Key with� NFC + Bluetooth?

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?omu

????? Tomu

What

about

you?

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FPGA Tomu

Tomu

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