MEMORY CONTROLLER PERFORMING SELECTIVE AND PARALLEL ERROR CORRECTION, SYSTEM INCLUDING THE SAME AND OPERATING METHOD OF MEMORY DEVICE

A memory controller is provided that is configured to control a memory accessed by a device connected to a host processor via a bus. The memory controller is configured to control a memory accessed by a device connected to a host processor via a bus, and includes a first interface circuit configured to communicate with the host processor; a second interface circuit configured to communicate with the memory; an error detection circuit configured to detect an error present in data received from the second interface circuit in response to a first read request received from the first interface circuit; a variable error correction circuit configured to correct the error based on at least one of a reference latency and a reference error correction level included in a first error correction option; and a fixed error correction circuit configured to correct the error in parallel with an operation of the variable error correction circuit.