A Mobile 3-D Display Processor With A Bandwidth-Saving Subdivider

Abstract

A mobile 3-D display processor with a subdivider is presented for higher visual quality on handhelds. By combining a subdivision technique with a 3-D display, the processor can support viewers see realistic smooth surfaces in the air. However, both the subdivision and the 3-D display processes require a high number of memory operations to mobile memory architecture. Therefore, we make efforts to save the bandwidth between the processor and off-chip memory. In the subdivider, we propose a recomputing based depth-first scheme that has much smaller working set than prior works. The proposed scheme achieves about 100:1 bandwidth reduction over the prior subdivision methods. Also the designed 3-D display engine reduces the bandwidth to 27% by reordering the operation sequence of the 3-D display process. This bandwidth saving translates into reductions of off-chip access energy and time. Consequently the overall bandwidth of both the subdivision and the 3-D display processes is affordable to a commercial mobile bus. In addition to saving bandwidth, our work provides enough visual quality and performance. Overall the 3-D display engine achieves 325 fps for 480x320 display resolution.