The VGA-CharGen is a memory-mapped, pipelined VGA text/character generator written in Verilog. Intended to be used with soft processors, old-school computers, or other SoC-like environments, an attribute/character RAM is provided, operating in the host system's clock domain independent from the video logic. This control interface is modeled after the old VGA (as in IBM's VGA) Mode 3.
In order to achieve pixel clock speeds sufficient for 1920x1080@60Hz and beyond, the VGA-CharGen breaks up the memory access and video generation into many small operations, occurring concurrently. At present, this pipeline of activities is 7-stages deep from the perspective of the video clock. (The external host clock for writing into the dual-ported attribute/character RAM is independent).
VGA-CharGen providing a memory-mapped text interface at 640x480@60Hz for an educational MIPS soft-processor
Resolutions exceeding 1920x1080@60Hz (shown here) are possible
