A METHOD OF UPDATING PROGRAM CODE FOR AN OPTICAL DISC DRIVE MICROCONTROLLER AND AN OPTICAL DISC DRIVE

摘要

An optical disc drive includes a system controller (1) in the form of a microcontroller and a FLASH memory (22) which holds program code for the microcontroller. The FLASH memory is formed in two areas, the first being a protected area in which the code cannot be changed and the second being an unprotected area in which the microcontroller can write updated program code. The updated code is received from a host computer over an interface (28). The code in the protected area and in the microcontroller ROM is sufficient to enable the basic functions of requesting and receiving program code from the host computer and writing the received program code into the unprotected area of the FLASH memory to be performed. This enables recovery of the drive if the code in the unprotected area becomes corrupted, for example if a power supply failure occurs during transfer of the code.