A 512Mb 2-Channel Mobile DRAM (OneDRAM TM) with Shared Memory Array

A 1.8V, 512Mb two-channel synchronous mobile DDR SDRAM (OneDRAM TM) with 333Mbps/pin was designed, with 90nm technology. The device can operate as 2 separate mo- bile 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.