Data processing system including memory systems coupled through internal channel

A data processing system comprising:

• a first memory system including a first nonvolatile memory device and coupled to a host through a first external channel;
• a second memory system including a second nonvolatile memory device and coupled to the host through a second external channel;
• and
• an internal channel suitable for coupling the first and second memory systems with each other,
• wherein the host, when read-requesting first and second data to the first memory system, transfers a first external channel control information for selecting sole use of the first external channel or simultaneous use of the first and second external channels, to the first and second memory systems,
• wherein the first memory system, when the first external channel control information indicates simultaneous use, outputs the first data to the host through the first external channel and outputs the second data to the second memory system through the internal channel, and
• wherein the second memory system, when the first external channel control information indicates simultaneous use, outputs the second data inputted from the first memory system through the internal channel, to the host through the second external channel.