Palm-Bus: Represents a master-slave interface with a single-master intended for Communications between the CPU and peripheral blocks. It is not used to access memories. it is also designed with low-power consumption in mind. 
The most distinctive feature of the core-frame is the separation of the I/O and and memory transfers on different buses. The Palm-bus provides for the I/O back plane and allows the processor to configure and control while the M-bus provides a DMA connection from peripherals to main memory, allowing direct data transfer without processor intervention.
 
    3. Core-Connect Protocol: Developed by IBM Blue Logicâ„¢,  provides three buses for interconnecting cores, library macros, and custom logic .(Processor Local Bus (PLB) ,On-Chip Peripheral Bus (OPB) and Device Control Register (DCR)).