| 摘要 |
A system is provided to support programming the size of a board-specific boot ROM in an embedded control system. Depending on functions performed by the embedded control system, a manufacturer decides which storage size of the boot ROM is required. An EEPROM of the embedded system is programmed to represent the selected boot ROM size. A network interface that provides data communications between the embedded control system and a data network has a boot ROM size detection circuit that supports boot ROM size programming. The boot ROM size detection circuit includes a ROM range register programmable from the EEPROM, and a boot ROM base address register programmable by an embedded controller via a PCI bus. During a power up process, the boot ROM size data from the EEPROM are loaded into the ROM range register. The embedded controller writes a predetermined value into the boot ROM base address register so as to read information representing the selected boot ROM size. Based on this information, the embedded controller assigns memory addresses in the network interface for the boot ROM of the selected size.
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