StelVideo: video signal generator for the Stellaris LaunchPad.
Copyright (C) 2013 Boris Gjenero <boris.gjenero@gmail.com>

Building
--------

This was developed using Code Composer Studio Version 5.2.1.00018.
Copy Stellaris LaunchPad Project 0 and then import these files.

Monitor Connections
-------------------

VGA sync inputs are TTL compatible, and compatible with LaunchPad levels.
You can connect them directly.

PB3: Vertical sync (DE-15 pin 14)
PB6: Horizontal sync (DE-15 pin 13)

Colour inputs are terminated with 75 ohm, and need 0 to 0.7V analog
signals. A resistor is used to drop the voltage and prevent overloading
the pin.

PA5: Connect via 220 ohm resistor to a colour input. (Green is DE-15 pin 2.)

GND: Connect to ground. (You can use DE-15 pin 5.)

Graphics mode
-------------

Video data is output from SSI. Interrupts and DMA provide data to SSI.
A timer triggers DMA which fills the SSI FIFO. Then an interrupt starts
SSI DMA for the rest of the line. Another interrupt happens once per
line, keeps track of vertical position, and performs setup for each line.

The frame buffer is in 16 bit little endian format, with most significant
bit being sent first. This means that compared to the usual arrangement,
both bits in a byte and pairs of bytes are reversed. This conversion
may be accomplished via img2fb.c.

A frame buffer is not included. One may be created from any image.
First, convert the image to .mono format using ImageMagick, and crop
to 496x640. Then, supply that file as an argument to img2fb and redirect
output to fb.h.