A hierarchy transaction-level architecture consisting of physical layer, transport layer, transaction layer and application layer can improve system-on-a-chip (SOC) verification reliability and efficiency greatly. Transport layer of the hierarchy transaction-level architecture is responsible for end-to-end message transmission between software side and hardware side without caring about modules of upper layers. Time division multiplexing access (TDMA) scheme is used for logic multi-channel transmission by mapping to the unique physical channel, or PCI bus, in the hierarchy transaction-level architecture. To implement multiplexing of logic channels, a communication protocol of transport layer is required to be self-defined and will be presented in the paper, including method to realize end-to-end communication, definition format of a data packet and its header. Experiment result demonstrates the self-defined communication protocol can work efficiently.