Semiconductor foundries offer prototyping services where they will place a micro-processor design on Wafer with numerous other prototypes. When the wafer is then cut into individual Dies, each customer receives its prototypes back for testing. The customer will then often be describes as ‘sampling’ the prototype device.
Production of devices on a wafer is heavily discounted, if not actually free. The reason is that the devices made and tested on the shuttle will have targeted the foundry’s process and will therefore probably be somewhat incompatible with another foundry – thus a shuttle is somewhat of a “loss-leader” for the foundry, since it can lock in the customer to making the production process in that foundry.
Shuttles are run by major foundries periodically, with target dates for submitting prototype designs for incorporation in a shuttle run. A typical shuttle will result in 150-400 test chips.