Design and operation of stretcher, swap and replicate gate in current access bubble memory device

Various structures necessary to realize dual conductor current-access bubble memory functions of swap gate, replicate gate, and stretcher, were designed by computer simulation. The device operations were confirmed for typical (YBi)3(GaFe)5O12bubble film. The simulation was based on drive-field data obtained experimentally using scaled models of the conductor sheets. The computer simulation shows that minimum current densities of the swap and the replicate gates can be as small as 0.3 mA/μm with bias margins of 15.1 and 12.3 %, respectively. The operating margin of the stretcher is 4.7 % at the same current density, but increases to 6.8 % when the current density is increased to 1.0 mA/μm. The paper describes the results of the computer simulation and discusses the possible reduction in power dissipation when a chip partition scheme is employed.