Intel 386 manual Interfacing

I/O INTERFACING

OE#

a·BIT1/0 DEVICE

OE#

BE3#

BE2#DECODE t -- _....

BE1#

BEO#

231732i8·1

Figure 8-1. 32-Bit to 8-Bit Bus Conversion

Another technique for interfacing with 8-bit peripherals is shown in Figure 8-1. The 32-bit data bus is multiplexed onto an 8-bit bus to accommodate byte-oriented DMA or block transfers to memory-mapped 8-bit I/O devices. The addresses assigned to devices connected to this interface can be closely spaced because only one 8-bit section of the data bus is enabled at a time.

8-3