5.9.1 Overview

Whenever an application needs information which is stored in a file somewhere in a remote location, the application can use the Host File Download feature to retrieve the file from the remote location and temporarily store it in the WINC’s Flash. When a download is successfully completed, a file handler is generated and stored in NVM in the WINC, therefore it is valid even after a WINC reset. After a handler is generated, access to the file is possible via the provided APIs and reading of a file is possible via two mechanisms, HIF and SPI. In either case, the read operation requires the file handler of the file which the application is trying to access, if the handler being requested and the handler internally stored match, then the access is granted. The same procedure is valid for erasing the file. The use of a file handler avoids access to invalid data, for example when trying to concurrently access the file. The following figure depicts the steps which the WINC follows when performing a Host File Download.