| 摘要 |
A circuit that automatically detects whether an input/output expansion board is connected to an EISA system or an ISA system. The circuit monitors the expansion bus for EISA slot-specific I/O cycles by sampling the bus signals AENx and BALE when either of the IORC, or IOWC, signals are asserted. When the circuit detects an EISA slot-specific I/O operation on the expansion bus, a signal is generated indicating that the expansion bus is the EISA bus. This determination allows an ISA expansion board to take advantage of certain EISA features when it is connected to an EISA system. Using a circuit to determine expansion bus type removes the need for a jumper to provide the same function, thus providing greater ease of use.
|
