Lots of chip companies do this. I worked for a company that sold a whole line of different chips at different price points that all used the same die. They had

Lots of chip companies do this. I worked for a company that sold a whole line of different chips at different price points that all used the same die. They had different packages and they all had different internal pads on the die connected to ground so that the chip could detect what mode it was in. The firmware could read this and detect which hardware was enabled or disabled. I remember the management being very secretive about this since they didn't want their customers to think they were being ripped off by buying the "expensive" chip… I don't meant to sound critical of this practice… From an cost perspective it makes a lot of sense to do it this way—the cost to layout, test, and create all the masks for a custom chip is huge. So it makes sense to want to cram as much into one chip instead of making 2 or 3 or 4. That way the one time cost of creating the masks and tooling up at the foundry are amortized over all the products that use the die.