公开(公告)号：AT191803T

公开(公告)日：2000-04-15

申请号：AT94306613

申请日：1994-09-08

Applicant: IBM

Inventor： ARIMILLI RAVI KUMAR ,  GREGOIRE DENNIS GERARD ,  YOUNGS AMY MAY

IPC: G06F12/08

Abstract: A data processing system and method dynamically changes the snoop comparison granularity between a sector and a page, depending upon the state (active or inactive) of a direct memory access (DMA) I/O device 20, 22 which is writing to a device 7 on the system bus 5 asynchronously when compared to the CPU clock 1. By using page address granularity, erroneous snoop hits will not occur, since potentially invalid sector addresses are not used during the snoop comparison. Sector memory addresses may be in a transition state at the time when the CPU clock determines a snoop comparison is to occur, because this sector address has been requested by a device operating asynchronously with the CPU clock. Once the asynchronous device becomes inactive the system dynamically returns to a page and sector address snoop comparison granularity.

公开(公告)号：DE69423938T2

公开(公告)日：2000-10-12

申请号：DE69423938

申请日：1994-09-08

Applicant: IBM

Inventor： ARIMILLI RAVI KUMAR ,  GREGOIRE DENNIS GERARD ,  YOUNGS AMY MAY

IPC: G06F12/08

Abstract: A data processing system and method dynamically changes the snoop comparison granularity between a sector and a page, depending upon the state (active or inactive) of a direct memory access (DMA) I/O device 20, 22 which is writing to a device 7 on the system bus 5 asynchronously when compared to the CPU clock 1. By using page address granularity, erroneous snoop hits will not occur, since potentially invalid sector addresses are not used during the snoop comparison. Sector memory addresses may be in a transition state at the time when the CPU clock determines a snoop comparison is to occur, because this sector address has been requested by a device operating asynchronously with the CPU clock. Once the asynchronous device becomes inactive the system dynamically returns to a page and sector address snoop comparison granularity.

公开(公告)号：ES2144488T3

公开(公告)日：2000-06-16

申请号：ES94306613

申请日：1994-09-08

Applicant: IBM

Inventor： ARIMILLI RAVI KUMAR ,  GREGOIRE DENNIS GERARD ,  YOUNGS AMY MAY

IPC: G06F12/08

Abstract: A data processing system and method dynamically changes the snoop comparison granularity between a sector and a page, depending upon the state (active or inactive) of a direct memory access (DMA) I/O device 20, 22 which is writing to a device 7 on the system bus 5 asynchronously when compared to the CPU clock 1. By using page address granularity, erroneous snoop hits will not occur, since potentially invalid sector addresses are not used during the snoop comparison. Sector memory addresses may be in a transition state at the time when the CPU clock determines a snoop comparison is to occur, because this sector address has been requested by a device operating asynchronously with the CPU clock. Once the asynchronous device becomes inactive the system dynamically returns to a page and sector address snoop comparison granularity.

公开(公告)号：DE69423938D1

公开(公告)日：2000-05-18

申请号：DE69423938

申请日：1994-09-08

Applicant: IBM

Inventor： ARIMILLI RAVI KUMAR ,  GREGOIRE DENNIS GERARD ,  YOUNGS AMY MAY

IPC: G06F12/08

Abstract: A data processing system and method dynamically changes the snoop comparison granularity between a sector and a page, depending upon the state (active or inactive) of a direct memory access (DMA) I/O device 20, 22 which is writing to a device 7 on the system bus 5 asynchronously when compared to the CPU clock 1. By using page address granularity, erroneous snoop hits will not occur, since potentially invalid sector addresses are not used during the snoop comparison. Sector memory addresses may be in a transition state at the time when the CPU clock determines a snoop comparison is to occur, because this sector address has been requested by a device operating asynchronously with the CPU clock. Once the asynchronous device becomes inactive the system dynamically returns to a page and sector address snoop comparison granularity.