CONTROLLER FOR COMPOSITE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a controller which can function as a host bridge of a PCI bus and also as a satellite. SOLUTION: The value of an external switch 1111 is read by a CPU 401, and the CPU 401 writes the read value by itself into a configuration register placed on a PCI interface 416 if the value has a high level. Then a configuration cycle is started to a device existing on a PCI bus. If the said value has a low level, the configuration cycle is waited for against a host existing on the PCI bus.