"The PXbus is the internal bus between the core, the DMA/bridge, the LCD controller, and the memory controller as shown in Figure 3-1. This bus is clocked at 1/2 the run mode frequency. For optimal performance, the PXbus should be clocked as fast as possible. For example, if a target core frequency of 200 MHz is desired use 200-MHz run mode instead of 200-MHz turbo mode with run at 100 MHz. Increasing the PXbus frequency may help reduce the latency involved in accessing non-cacheable memory"