Intel 386 - Manual (Page 375)

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
12-40
12.3.9 Mode 2 Register (DMAMOD2)
Use DMAMOD2 to select the data transfer bus cycle option, specify whether the requester and
target are in memory or I/O, and determine whether the DMA modifies the target and requester
addresses. If you set up the DMA to modify the requester address, use DMAMOD2 to determine
whether the DMA increments or decrements the requester address during a buffer transfer.