This part is a kind of semiconductor called JMB385.

Function of this product has PCI Express to x1 Combo Memory Card Host Controller.

Manufacturers : JMicron

Image and pinout :

Some of the text within the PDF file :

JMB385 JMB385 PCI Express to x1 Combo Memory Card Host Controller Overview JMB38X is product family that includes 1394a OHCI and Memory Card Reader Host Controller. They are all 1-lane PCI Express to 1/2-port 1394a and 1-slot Combo Memory Card Reader (SD/MMC/MS/xD) Host Controller. The table below shows the brief feature lists of JMB38X product family. JMB380 Host IF 1394a IF Card Reader PCIe x1 Port x1 Combo** JMB388 PCIe x1 Port x1 Combo** JMB381 PCIe x2 Port None JMB385 PCIe None x1 Combo** LQFP48 Package Version On-board Application Add-on / Express Card Application SDXC UHS-1 D3E EEPROM Boot Function CR1_CD2 Co-layout --X X V X X V X V V X V* V V V X V X X --V X X V X X -V V X -V www.DataSheet.co.kr JMB387 PCIe None x1 Combo** JMB389 PCIe None x1 Combo** LQFP48 QFN48 -C Q [ ... ]

JMB385 PDF Datasheet Download