The 128-bit FPD main switch is one of the switches in top-level interconnect that connects the FPD masters to the LPD slaves (including the OCM and TCM). The switch provides a direct path to the OCM (bypassing the LPD interconnect) to minimize latency and improve throughput from the FPD to the OCM. In addition, the switch provides a separate (narrow) path to access the LPD peripheral registers by the FPD masters.