The LEON2 is based on an AMBA AHB/APB bus architecture, so new modules can easily be added to extend its functionality.
Advanced Microcontroller Bus Architecture. AMBA was introduced by ARM in 1996. The first AMBA buses were Advanced System Bus (ASB) and Advanced Peripheral Bus (APB). In its second version, AMBA 2 in 1999, ARM added AMBA High-performance Bus (AHB) that is a single clock-edge protocol.