RTS5261

Last year the SD Association published its Secure Digital 7.0 standard that defines SD Express cards. At this year’s Computex, Realtek demonstrated one of the industry’s first SD Express controllers for appropriate card readers. The RTS5261 chip already exists in silicon, so it is a matter of time before it is used for actual products. As per SD 7.0 specification, SD Express cards have to support both UHS-I as well as PCIe 3.0 x1 interfaces using different sets of pins (UHS-I for SD, UHS-II/III for PCIe). Therefore, SD 7.0 controllers have to support both protocols, legacy features of SD, capabilities of PCIe (bus mastering/DMA, command queuing, Host Memory Buffer, etc., as well as new features offered by NVMe 1.3 (e.g., power states). Realtek’s RTS5261 supports everything...