Would that be the kind of decoding you had in mind ? 0x80: Ox00E00003 - Memory Mapped I/O Base 0 DRAM Base: 0x00E0000000 Read Enable: 0x1 Write Enable: 0x1 Interleave Enable: No interleave 0x84: Ox00EFFF80 - Memory Mapped I/O Limit 0 Dst Node ID: 0 Interleave select: 0b111 DRAM Limit: 0x00EFFFFFFF -- Vincent Legoll