VHDL Bitstream DAC
The VHDL file implements a bitstream DAC. To use it, for a crude DAC, simply attach a low-pass-filter to the output of the digital output pin. In some cases, you don't even need an LPF (since speakers, motors, etc. inherently low-pass filter). For a high-accuracy DAC, add a precision register to make sure the transitions are well-timed, and a clipping circuit, to make sure the the high and low levels are very consistent from cycle to cycle. At a high clock speed, this can give a very linear, reasonable accuracy DAC.
The DAC was tested, and worked adequately well for my purposes (although it was used as a quick-and-dirty hack for a low precision project).
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