Method of upgrading software of cable modem

摘要

PURPOSE: A method for upgrading a software of a cable modem is provided to operate a cable modem stably although a network download is occurred by using two image banks. CONSTITUTION: A program is booted from a boot ROM image stored in the first flash memory when an initial power source is inputted(312). The boot ROM image performs a system initialization process as a memory RAM, an I/O port initialization and a task creating(314). Parameter data stored in the first flash memory are read(316). The program checks whether the boot image is "0"(318). If the boot image is "0", the first bank image is copied to a DRAM(322). If the boot image is "1", the second bank image is copied to a DRAM(324). A cable modem operation is performed by rendering a program counter to be moved to address starting address of the DRAM. The program continuously checks the on/off state of a factory default switch and with respect to a network download and the first bank copy enable state while the modem is operated normally(328, 334, 344). If the factory default switch is pressed, the program detects the state, and sets the boot image to "0", and stores the boot image in a parameter storing NVRAM of the first flash memory and resets at the initial state(332). A download is turned on through a cable network by a control method of an SNMP or a configuration file of a cable modem during operating of a program(334), the program down-loads new software image code to the second bank stored in a remote server by using a TFTP method(336). If the network is stopped, the program stores the boot image to "0" in the parameter storing NVRAM of the first flash memory.