公开(公告)号：JPH08235102A

公开(公告)日：1996-09-13

申请号：JP29867995

申请日：1995-11-16

Applicant: APPLE COMPUTER

Inventor： KEBIN EMU KURISUCHIYANSEN ,  DEIBUITSUDO BUI JIEIMUSU ,  BURUUSU II EKUSUTAIN

IPC: G06F13/28

Abstract: PROBLEM TO BE SOLVED: To provide a system and method for designating a substitute data stream and memory address space during a DMA transferring period. SOLUTION: The key field of a channel command is constituted so that the use of a substitute data port instead of a standard data stream can be designated. The data port can be formed in an unaddressed substitute data stream, such as the control/status steam, etc., or in another addressable space, such as the system memory, input-output address space, channel register space, etc. When a second addressable space is designated, another channel register is used for storing secondary addresses.