DNLD process is used to upload the IOS when IOS is in rommon mode and we are unable to upload the IOS in normal way because router don’t have nay IP address or any other configuration so we can upload the IOS using normal process. in this case we can upload the IOS using DNLD process or through X-Modem. Below is the DNLS process and X-modem process , i will explain in another post.
Just remember the one word that is TFTPDNLD , other command syntax will be show on console when you runs the tftpdnld. so no need to remember all the commands. Before follow the below process , your desktop / laptop should be connected with router using straight or cross cable and console cable as well as make sure you are having tftp server application on your laptop and IOS image. also make sure that you have given the path of IOS in application and TFTP server application taking the IP address of your laptop.
Rommon> dir flash: