The APB Channel provides the necessary infrastructure to connect as many as 16 AHB Slaves (numbered 0-15) to an APB Bus Master. The APB Channel performs a combinational decode on the incoming APB address to produce the block selects for the various APB Slaves.
Typically, the APB Channel is connected as in the following description. Each of the APB Channel’s 16 Mirrored Slave Ports is connected to an APB Slave module (e.g. Timer, UART, GPIO). On the Master side, the APB Channel’s Mirrored Master Port typically is connected to an AHB to APB Bridge module.