VintageBusFPGA_Common

Common stuff for SBusFPGA, NuBusFPGA

Content

• goblin_fb.py: 'Goblin', a Framebuffer (bit-mapped graphic display), supporting 1/2/4/8/16/32 bit depth, a single hardwired resolution to the screen, and windowboxed lower resolution. Also uses fb_dma.py (to read the framebuffer content from a LiteDRAM controller) and fb_video.py (timing generator). Originally based on Litex's own framebuffer code.

• goblin_accel.py: acceleration engine for the 'Goblin' framebuffer. Basically a custom VexRiscv core (VexRiscv_GoblinAccel_NuBus.v or VexRiscv_GoblinAccel_SBus.v) and some firmware (the blit_goblin*.* files).

• cdc_wb.py: a custom wrapper around alexforencich's wb_async_reg.v, a Wishbone DCD component. Feature a customizable time-out to avoir the fast side overloading the slow side (a bit hackish but it works for my use case).

• fpga_blk_dma.py: a block DMA between a LIteSDRAM port and a set of FIFOs. Used to create burst (SBus) or block (NUbus) accesses from the device to the host memory. Used by RAM-based "disks".

• wb_master.py: A small Wishbone master (originally from enjoy-gigital) that can do basic read/write/wait commands. Used to configure the DDR3 controller w/o firmware.

• FLASH+TEMP-PMOD: a PMod-like module with a SPI NOR Flash device & a I2C temperature sensor. Can be used with the SBusFPGA were both feature are supported. On NuBusFPGA currently the I2C bus is not supported in MacOS. The Flash is currently usable to store the ROM for the device (Forth code for SBusFPGA, Declaration ROM for NuBusFPGA). The temperature sensor is supported in NetBSD 9.0 in SBusFPGA.

• PI2PMODSPI: a simple PCB to route the SPI bus from a Raspberry Pi to the appropriate pins on the FLASH+TEMP-PMOD above. Makes it easier to program the Flash NOR in the PMod with 'flashrom' on a Raspberry Pi.

Not included:

• Other framebuffers: SBusFPGA has other framebuffers (1-bit bw2, 8-bit cg3, accelerated 8-bit cg6) that 'emaulate' (in a limited way) vintage framebuffers. SBus-specific.

• TRNG: a small True Random Number Generator, based on an old version of the neorv32's trng. Should be moved here, currently only in SBusFPGA.

• USB: Dolu1990's OHCI USB controller & standard Litex wrapper.

• SDRAM: standard LiteDRAM controller.

• Crypto engine: a very customized version of the Betrusted.IO crypto engine, featuring AES and GCM support and a Load/Store unit. Should be moved here, currently only in SBusFPGA.

• sdcard: standard LiteSDCard controller.