Analog and Video in F21
On Wed, 16 Nov 1994, Jeff Fox wrote:
> Video:
> Input and output will be supported. Software should provide genlock and
> video overlay, digitization, and decoding of digital information in a
> standard video signal format. 4 bit resolution like MuP21, but with
> a potentially higher clock rate. 3 more pins have been provided for
> RGB output in addition to composit.
This is interesting. The last time I read info on the F21 I thought it
will have only one video output, which can be either composite, or one of
the RGB signals. Now I see, that one F21 will be needed to produce and
RBG signal.
How will it be done? Will each pin have 4 bits of resolution, so one will
have to specify a pixel with 12 bits, or the old 16 colors will apply? In
case one uses 12 bits, how frequently will the video coprocessor have to
access the DRAM? Will there bit one 20-bit read for one 12-bit pixel?
> Analog:
> The analog i/o coprocessor will be fast enough for 6 bit video (14 mhz)
> but will normally be used for audio.
So if three F21s are used in concert to generate RGB video, then one
could in priciple go 18-bit RGB?
> Higher resolution than 6 bits will
> be available with oversampling and pwm techniques.
What is a good book for mathematically understanding those?
--
Penio Penev <Penev@venezia.Rockefeller.edu> 1-212-327-7423
