Intel manual 2 82385/lnte1386 OX Microprocessor Interface

CACHE SUBSYSTEMS

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i3B6'"ox CPU

LOCAL BUS

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82385

LOCAL BUS

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SYSTEM BUS

231732i7-11

Figure 7-11. Intel386™ OX Microprocessor/82385 System Bus Structure

bus. The 82385 local bus is not simply a buffered version of the Intel386 DX micropro- cessor local bus, but rather is distinct from and able to operate in parallel with the Intel386 DX microprocessor local bus. The 82385 directly interfaces to the Intel386 DX microprocessor on the Intel386 DX microprocessor local bus.

7.7.2 82385/lnte1386 OX Microprocessor Interface

The 82385 directly interfaces to the Intel386 DX microprocessor. It has three inputs which are used to decode Inte1386 DX microprocessor local bus accesses, non-cacheable memory accesses, and 16-bit accesses. It runs fully synchronously with the Intel386 DX microprocessor and returns data with a full 32-bit data bus. The Intel387 DX math coprocessor also resides on the Intel386 DX microprocessor local bus.

7.7.2.1 Intel386 OX MICROPROCESSOR INTERFACE

The connections between the Intel386 DX microprocessor and the 82385 are shown in Figure 7-12. As can be seen, the 82385 interfaces directly to the Intel386 DX micropro- cessor. The 82385 setup specifications for the Intel386 DX microprocessor address and control bus are designed to meet the Intel386 DX microprocessor output delays.

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