Electrical computers and digital data processing systems: input/ – Intrasystem connection – Bus access regulation
Patent
1998-06-15
2000-10-03
Auve, Glenn A.
Electrical computers and digital data processing systems: input/
Intrasystem connection
Bus access regulation
711114, G06F 1300
Patent
active
061286869
ABSTRACT:
An embodiment of the present invention discloses a technique for concealing a peripheral memory transaction on a local bus within a peripheral controller from a host system bus. In the preferred embodiment both the local bus and the host system bus are PCI buses. The technique is implemented when a peripheral memory transaction is detected on the local bus. In a disclosed embodiment, the peripheral memory transaction is detected by monitoring command and byte enables (CBEs) and five upper address bits (AD[31::27]) of the local bus. A peripheral memory transaction is indicated when a memory transaction on the local bus is directed to an upper 128 MB of 4 GB host memory. When a memory transaction is detected to the upper 128 MB of memory the transaction is intercepted. The interception is accomplished by blocking the CBEs on the local bus from a peripheral interface.
The peripheral interface in the preferred embodiment is a standard PCI--PCI bridge which couples the local bus to the host system bus. After being intercepted, the CBEs are recoded so that the memory transaction does not appear on the host system bus. In the disclosed embodiment the memory CBEs are recoded to reserved CBEs of the same parity as the memory CBEs. An advantage of the present invention is that a standard PCI--PCI bridge can be utilized to interface the peripheral controller to the host system bus.
REFERENCES:
patent: 5150465 (1992-09-01), Bush et al.
patent: 5241630 (1993-08-01), Lattin, Jr. et al.
patent: 5249279 (1993-09-01), Schmenk et al.
patent: 5448709 (1995-09-01), Chandler et al.
patent: 5469548 (1995-11-01), Callison et al.
patent: 5717954 (1998-02-01), Grieff et al.
patent: 5737744 (1998-04-01), Callison et al.
patent: 5838932 (1998-11-01), Alzien
patent: 5918026 (1999-06-01), Melo et al.
Grieff Thomas W.
Jones Bryan A.
Sabotta Michael L.
Auve Glenn A.
Compaq Computer Corporation
LandOfFree
Hiding peripheral memory transactions on a local bus within a pe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hiding peripheral memory transactions on a local bus within a pe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hiding peripheral memory transactions on a local bus within a pe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-205383