Fixing the pixels

As I'd mentioned earlier, I had some problems with the clocking of the pixels. I was pushing the RAM chip a little too hard, and the data was attempted to be read in 5ns, whereas it should've been 10. This is what it looked like:

I inserted a clock delay for the write pulse to the FIFO, and that cured it.

Unfortunately, one of the things that happened late last night was that I reset the monitor, and now the sync settings are incorrect (I didn't realise it memorised it), so I'll need to play with the porch settings again. This has caused the top few lines to disappear. I didn't notice until I was preparing these pictures.

Circles

I've used just over half-way in the PicoBlaze memory, and seeing as the line algorithm didn't use up that much memory, I had a crack at the circle one as well.

And it ended up being quite a bit simpler than the line algorithm - less temporary storage required.

The command set was extended with:

• 0x27 - Draw circle with given radius

When added to the previous test, it looks like this: