A 512 mb 2-channel mobile DRAM (oneDRAM™) with shared memory array

A 1.8 V, 512 Mb two-channel synchronous mobile DDR SDRAM (OneDRAMtrade) with 333 Mbps/pin was designed, with 90 nm technology. The device can operate as 2 separate mobile DDR SDRAMs through each channel because of its exclusive accessibility from each channel to dedicated memory arrays. A new control scheme is proposed to exchange data between two channels by sharing one common memory array. The shared memory array control scheme is based on direct addressing mode to achieve compatibility with normal SDRAM interface together with fast data transfer speed between two channels.