This part is a kind of semiconductor called CH376.
Function of this product has file manage control chip.
Manufacturers : ETC
Image and pinout :
Some of the text within the PDF file :
The DataSheet of CH376 (the first) 1 File manage and control chip CH376 English DataSheet Version: 1 http://wch.cn http://wch-ic.com 1. Introduction CH376 is used as file manage control chip, used to MCU system read/write file in USB Flash Drive or SD card. CH376 supports USB-Device Mode and USB-HOST Mode. Set the basic firmware of USB communication protocol in the inner. It is also set firmware of special communication protocol to deal with Mass-Storage devices, communication interface firmware of SD card, FAT16, FAT32 and FAT12 file system manage firmware in the inner. It supports common USB storage devices (contains USB Flash Drive/USB hard disk/USB Flash memory/USB read card) and SD cards (contain SD card with standard capacity and HC-SD card with high capacity, MMC card and TF card [ ... ]