This effect was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
This is a linear step tile
In other words it tiles in a 1-2-3-4 prgresseve manner instead of mathmatical
1-2-4-8
this filter allows for up to 12 divisions and allows for all 4 directions
This eddition adds the blended 90 step tile mode to linear step tile
step tile linear 45 blend 90