August 22, 2007 -- There has been an increasing demand to add multiple Secure Digital (SD) devices in a single system. The problem, however, is that most host devices/ processors, for example Intel PXA270, TI OMAP, or Qualcomm MSM processors, only provide a single SD interface. Fortunately, complex programmable logic devices, otherwise known as CPLDs, can be used to allow host devices to support any number of SD devices. This article details a scalable, auto-sensing bidirectional multiplexer-based design.
By Mark Ng. (Ng is a Staff Applications Engineer in CPLD Applications at Xilinx, Inc.)
This brief introduction has been excerpted from the original copyrighted article.