Apple’s “A5 die is dramatically larger than the A4,” Paul Boldt and Don Scansen report for EETimes. “Both UBM Techinsights and Chipworks found the A5 die to be 12.1 mm x 10.1 mm, giving a die size of 122 mm2. This compares to 53 mm2 for the A4. The die size of the A5 is therefore 2.3 x larger than the A4.”
“Let’s look closer at the A4 and A5 floorplans and consider what might be behind such a dramatic increase in die size for the A5,” Boldt and Scansen report.
“If you were Apple what would your strategy be? We do know there is quite a bit of real estate on the A5 beyond the CPU+GPU+arbitration, and the necessary IP blocks for memory control, I/O etc. So what to do with this extra real estate… Bold is the only word that can be used to describe Apple’s A5. It was bold to design such a large device. Certainly the CPU+GPU combination is significantly larger than the comparable portion of the A4. However, this is only the beginning of the story. Going beyond these basic elements leaves an additional 34 mm2 or 64 percent of the whole A4 die. Yes, there are very likely additional IP cores there, but there might also be some clever custom design that leverages Apple’s integrated approach.”
Boldt and Scansen report, “Apple likely plans to venture further down the road of custom circuit design. Going beyond the need to remain generic and flexible to accommodate the broadest possible OS market might produce revolutionary hardware-software platforms.”
Much, much more in the full article – recommended – here.