Runs DMA writing with slave DMA emulation mode with the local DMA controller the manner

摘要

PROBLEM TO BE SOLVED: To emulate slave DMA operation on a computer system dedicated to a master by performing DMA transfer by a local DMA controller through the computer system bus dedicated to the master and informing emulation logic. ;SOLUTION: In DMA transfer in full DMA mode, the local DMA controller receives a word count, a base address, and a direction (step 301). Further, application software operating in a host computer system makes a request for DMA data transfer and the local DMA controller receives the request from the emulation logic (step 302) and performs transfer through the bus (step 303). Then the local DMA controller updates an internal address, a word count, and a state register (step 304) and informs the emulation logic of the completion of the transfer (step 305).;COPYRIGHT: (C)1998,JPO