SAN FRANCISCO, Calif. Toshiba described Wednesday (Feb 10) a novel mobile media processor it is now sampling using stacked custom DRAM, one of a handful of such devices discussed at the International Solid State Circuits Conference (ISSCC).
Renesas Technology also showed a media processor for digital TVs. In addition, Intel Labs, and academics showed various highly parallel research chips for handling media or object recognition.
All the chips underscored a move to use of multiple kinds of cores to handle an increasingly varied set of media applications. Some raised a call for reconfigurable processors or parallel arrays to handle jobs such as face and object recognition.
One mantra all the engineers shared was the need to optimize designs for the best performance per Watt while keeping die size at a minimum.
"Mobile image processors [for example] are limited to less than 500 mW, and their price has become less than $5 so area efficiency is required," said Takashi Kurafuji, author of one of two papers from Renesas.
Toshiba showed a media processor sandwiched between a mobile DDR and a custom DRAM using novel packaging technology. Toshiba is sampling the device now as a merchant chip. Its cost was not immediately available but is presumably high given the use of a custom DRAM and packaging technology.
The 40nm device consumes just 222 mW to decode H.264 video at 30 frames/second. It can decode VGA-class video at 15 frames/s in software, consuming just 71 mW. It has leakage power of just 15 microW in standby and 1.7 mW in sleep mode.
A 6 x 6.2 mm logic chip at the heart of the package uses 14 cores including one ARM Cortex A9 MPCore. It also includes separate video, 3-D graphics and audio/video multiprocessing blocks.
A mobile DDR DRAM is stacked on top of the logic die using micro-bumps and wire bonding. A custom DRAM at the bottom of the stack rides on a so-called re-distribution layer as a substrate, uses micro-bumps and wire bonding and sports a 10.6 Gbytes/s memory bandwidth.
Toshiba would not identify the third party that supplies the DRAM. Toshiba creates the stack in-house in an assembly stage. The custom DRAM interface uses 85 percent less power in some operations than a traditional DDR interface, Toshiba said.