CACHE SUBSYSTEMS
The 82385 resides on the Inte1386 DX microprocessor local bus and interfaces directly to the Intel386 DX microprocessor. It presents a 'functional Inte1386 DX microprocessor bus (called the 82385 local bus) for the system interface. This dual bus structure and the 82385's ability to "snoop" the system interface allows the Inte1386 DX microprocessor to run locally out of the cache while another bus master has control of the 82385 local bus.
7.7.1 Bus Structure with the 82385
Figure 7-10 shows the bus structure of a typical Intel386 DX microprocessor system. The Intel386 DX microprocessor local bus consists of the physical Intel386 DX microproces- sor address, data, and control buses. The local address and data buses are buffered/ latched to become the system address and data buses. The local control bus is decoded by bus control logic to generate the various system bus read and write commands.
The addition of an 82385 creates two distinct buses: the actual Intel386 DX micropro- cessor local bus and the 82385 local bus (Figure 7-11). The 82385 local bus is functionally equivalent to the Inte1386 DX microprocessor local bus, with system resources interfac- ing to it in the same manner as they would with the Intel386 DX microprocessor local
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