The mpc555 has 446kB internal flash and 26kB internal ram. On the NTB MPC555 headerboard there is an additional 4MB external flash and 2MB external ram. All internal memory can be accessed within 2 clock cycles (2 * 25ns = 50ns @40MHz operating frequency). The external memory (RAM and flash) needs 2 extra bus wait states. This gives a total access time of 4 clock cycles. The complete memory map is described in the document below.
memorymap_ntb-mpc555-headerboard.pdf

The mpc5200B has 16kB internal ram. On the phyCORE-MPC5200Btiny headerboard there is additional flash and SDRAM. The complete memory map is described in the document below.
memorymap_phycore-mpc5200tiny.pdf

The mpc5200B has 16kB internal ram. On the phyCORE-MPC5200Bio headerboard there is additional flash, SRAM and SDRAM. Further, the board contains an configurable FPGA. The complete memory map is described in the document below.
memorymap_phycore-mpc5200io.pdf