25 Power Domains, 14-Core Application Processor With x512b Stacked DRAM

Abstract—In this paper we introduce a 14-core application processor for multimedia mobile applications, implemented in 40 nm, with a 222 mW H.264 full high-definition (full-HD) video engine, a 124 mW 40 M-polygons/s 3D/2D graphics engine, and a video/audio multiprocessor for various Codecs and image processing. The application processor has 25 power domains to achieve coarse-grain power gating for adjusting to the required performance of wide range of multimedia applications. The simple on-chip power switch circuits perform less than 1 s switching while reducing rush current. Furthermore, the Stacked Chip SoC (SCS) technology enables rewiring to the DRAM chip during assembly/packaging phase using a wire with 10 m minimum pitch on Re-Distribution Layer (RDL) using electroplating. The peak memory bandwidth is 10.6 GB/s with an x512b SCS-DRAM interface, and the power consumption of this interface is 3.9 mW at 2.4 GB/s workload. Index Terms—Application processor, full high-definition (full-HD) video, MICRO bump, multiple power domains, on-chip LV-PMOS switch, Re-Distribution Layer (RDL), stacked DRAM. I