Terminal device capable of remote download, download method of loader program in terminal device, and storage medium storing loading program

摘要

Memory is divided into a plurality of banks to store software which is upgraded one bank at a time. By doing so, a memory with the same size as one bank is only needed as the temporary storage used when performing an upgrade. The terminal device only needs a memory that is "1+1/n" times as large as a total software when there are n banks, while a conventional terminal device needs a memory that is twice as large as the total software. Two loader programs are stored in different banks as a master loader program used for download processing and a backup loader program. On receiving a new loader program, one loader program is used to write the new loader program over the other loader program so as to upgrade the loader program. The backup loader program is activated when the new loader program is to be written over the master loader program.