Electrical Design

Tiliqua consists of 3 PCBAs. All of these are open-hardware designs built in KiCAD and stored in separate repositories.

Block Diagram (Tiliqua R4)

Below is high-level picture of how all the different electrical components of Tiliqua are connected.

Some connections are omitted for simplicity (example: some ex0/ex1 pins are connected to both the ECP5 and RP2040, not shown).

We now follow with a summary of the core functions of each of the Tiliqua PCBAs.

Repository: tiliqua-motherboard

Rotary encoder with button and bar graph display.
RP2040-based JTAG debugger and UART bridge supported by openFPGAloader.
Two USB ports:
- dbg: USB FS for JTAG debugging.
- usb2: 480Mbit/sec USB HS PHY connected to FPGA. Device, host and dual-role operation is supported on this port with a dedicated TUSB322I CC control IC and +5V VBUS switch.
Display output for video synthesis
- Maximum resolution 1280x720p/60Hz or 1920x1080p/30Hz.
2x (PMOD-compatible) expansion ports for up to 24 simultaneous audio channels.
MIDI-In jack (TRS-A standard) with optoisolation.
External PLL (SI5351A) for dynamic display resolution switching.
Soft mute for pop-free bitstream switching

Repository: soldiercrab (see README there for more detailed docs on this SoM)

Lattice ECP5 (25 K) FPGA, supported by open-source FPGA toolchains
256 Mbit (32 MByte) HyperRAM / oSPI RAM (for long audio buffers or video framebuffers)
128 Mbit (16 MByte) SPI flash for user bitstreams
High-speed USB HS PHY (ULPI)

Repository: eurorack-pmod