Browse Prior Art Database

Dual slot 100MHz bus running single slot 133 MHz configuration

IP.com Disclosure Number: IPCOM000103664D
Original Publication Date: 2005-Mar-18
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 24K

Publishing Venue

IBM

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 61% of the total text.

Page 1 of 2

Dual slot 100MHz bus running single slot 133 MHz configuration

     In a two slot environment sharing a single bus, a 133 Mhz bus cannot support 2 slots at the same 133 Mhz speed, thus allowing only a 100Mhz max speed on the bus. Consequently, if a user only wants to operate a single 133Mhz card, only functionality at 100Mhz is permitted. However, the invention allows for the bus to run at 133Mhz if only one adaptor is present on the bus at bootup. This allows the user to fully utilize a single card at the 133Mhz speed by disabling the other slot to avoid failure. Furthermore, the invention does not limit the bus to only a single card. If two cards are present at boot time, both cards operate at the maximum allowable 100Mhz as normal operation. For the instance when zero cards are present at boot, the controller will not limit the system to only one expansion slot at 133, it allows for both slots to be hot added to 100 Mhz. This allows for a user only needing one slot to run it at 133 Mhz, without penalizing the users of 2 adaptors.

    The invention solves the problem of utilization for a single slot configuration allowing a single 133 Mhz adaptor to run at the maximum speed of 133 Mhz. To avoid limiting the bus to only one adaptor all the time, the invention only occurs at startup. The procedure goes as follows: *assume reference to all cards are PCI-X 133Mhz adaptors, all others operate as defined in the functionality spec. *the invention only applies to 133 Mhz adapto...