nextpnr (-ice40 for iCEBreaker, -ecp5 for ULX3S).

although an original SNES gamepad can be used. ***: PCB push buttons are used by default. **: Visual artefacts can been seen if more than one alpha-enabled layer intersects with another i.e. The 4x layer implementation is still included in this repo but was disabled due to VRAM usage constraints. *: Only one of these layer types can be enabled at any given time but they can be toggled multiple times in a frame using raster-timed updates. The system doesn't require any RAM beyond what is available in the iCE40 UP5K.

1060+ sprite pixels per line depending on clock and video mode.

256x sprites of up to 16x16 pixels each.

1x 1024x1024 pixel affine-transformable layer*.

3x or 4x scrolling layers up to 1024x512 pixels each*.

Optional alpha blending using 4bit alpha intensity**.

ARGB16 colors arranged into 16 palettes of 16 colors each.

Configurable video modes of or 4bpp graphics assembled from 8x8 tiles.

Custom multichannel ADPCM decoder / mixer (44.1KHz, 16bit stereo).

Custom 'copper' coprocessor integrated into VDP to perform raster effects.

Custom VDP for smooth-scrolling layers and sprites.

RISC-V CPU (configurable with VexRiscV or PicoRV32).

This along with other similarly copyrighted assets are not published here. Demo running on iCEBreakerĭemo with placeholder assets just for illustration. On the ULX3S, the onboard GPDI port is used for video output. **: iCEBreaker requires the additional 12bpp HDMI PMOD for video output.

Potentially boards with a 25F can be supported by moving the CPU RAM to external memory. It's been confirmed working on boards with Winbond flash but thought to work on others too. *: Only the ECP5-45F and 85F have the 128kbyte of block RAM required. Remaining work is mainly cleanup, adding more supported gamepads, more demos and possibly other optional non-core features.

It is feature-complete and confirmed working on both the iCEBreaker and ULX3S targets. This allows it to render 480p scenes from 64KByte. It uses character maps, sprites and raster effects to implement various effects. It's being developed using the open-source yosys and nextpnr tools and can be run on both the iCEBreaker** and ULX3S* boards.Īs a retro-inspired console, it does not use framebuffers, rasterizers, shaders etc. This is a compact open-source FPGA game console targetting the Lattice iCE40 UltraPlus series.

Video mode 640x480 software