You can reconfigure the ports to use switch/cpu as you please. The high end CCR devices, only use CPU as their focus is on routing and they have no switch chips. Some devices even has several switch chips. Most of the MikroTik devices can function both as a switch or as a router, either using the internal switch chip, using the CPU or a combination of the switch and CPU, to move packets. To move packets based on IP addresses, layer 3 is needed, and such a device is called a router. Switches work on the OSI Layer 2, which means that they don't know about IP addresses. If you attach another device to a port, the new NIC will have another MAC address, and the switch will again send the packet to all ports, to learn where the correct MAC address is now, and after that it will again operate point-to-point between the relevant ports. All MikroTik devices work as a managed switch, and all devices include the full RouterOS feature set. When the switch has learned which MAC addresses responds to which ports, it will only send the packets for the correct ports and save internal bandwidth (on the backplane). By default a switch will send packets to all connected ports each time it receives a new packet.

Mikrotik routeros what is master port