Title of Invention

"AN APPARATUS FOR ENSURING FEATURE COMPATIBILITY AND COMMUNICATING FEATURE BETWEEN PROCESSORS AND MOTHERBOARDS"

Abstract

A handshake mechanism is provided to allow feature competible processor and motherboard combinations to operate, and incompatible combinations to fail safely. The handshake mechanism also facilitates communication of feature settings between a motherboard and on attached processor. For each feature, the handshake mechanism includes connection pins correspondingly disposed on complementary connectors of the processors and the motherboards for conveying a feature setting selection signal for the feature. The handshake mechanism further includes particular manners for connecting the processors" connection pins and the motherboards" connection pins to their respective internal circuitry, depending on the manners the feature is supported by the various processors and motherboards.

Full Text

The present invention relates to an apparatus and a method for ensuring feature compatibility and communicating feature between processors and motherboards. BACKGROUND INFORMATION Microprocessors and related device technologies are continuing to advance at an ever increasing pace. From the processor and device manufactures perspective, the marketplace must be able to absorb these advances in technology as advancements are made. One hurdle to this absorption is the worry of equipment obsolescence. Before making investments into equipment, business and consumers want to know that there are migration paths for them to upgrade in an orderly manner, and preferably at times that are most advantages for them (driven by their needs, and not "forced" upon them by the equipment manufactures). Thus, compatibility between different generations of components/equipment is an important goal to strive for. The increasing pace of technological advancement has made the achievement of this goal even more: important. Conventionally, different sockets, slots, form factors, and/or mechanical keying are employed to ensure that only compatible processor and devices will be: used together. Additionally, manual "switches", such as jumpers would be employed to indicate the features and or feature settings supported. These conventional approaches to ensure compatibility and communicate features/feature settings suffer a number of disadvantages. First, approaches that use different sockets, etc. are costly. Multiple parts have to be manufactured, maintained, arid tracked. Second, approaches, that use manual "switches" are error-prone. Thus, a more cost effective and less error-prone approach to ensure feature compatibility and communicate feature settings between processors and motherboards is needed. SUMMARY OF THE INVENTION A handshake mechanism is provided to allow feature compatible processor and motherboard combinations to operate, and incompatible combinations to fail safely. The handshake mechanism also facilitates communication of feature settings between a motherboard and an attached processor, For each feature, the handshake mechanism includes connection pins correspondingly disposed on complementary connectors of the processors and the motherboards for conveying a feature setting selection signal for the feature. The handshake mechanism further includes particular manners for connecting the processors' connection pins and the motherboards connection pins to their respective intemal circuitry, depending on the manners the feature is supported by 'he various processors and motherboards. In one embodiment the feature is system bus speed, including a first and a second bus speed setting. The feature setting selection signal is a bus speed selection signal having a low and-a high state, with the low state selecting the first bus speed setting, and the highsute selecting the second bus speec. setting. For this embodiment, for processors that invariantly support only the first bus speed setting, their connection pins are connected to ground to drive the bus speed selection signals to the low state, For processors that variantly support either one of the bus speed settings, their connection pins are connected to pull-up resistors to pull the bus speed selection signals to the high state. For motherboards that invariantly support only the first bus speed setting, theirconnection pins are connected to ground to drive the bus speed selection signals in the low state. For motherboards that variantly support either ons of the bus speed settings, their connection pins are coupled to the clods select inputs of the variable system clocks OB the motherboards, to provide the variable system clocks with the bus speed selection signals. For motherboards that invariantly support the second bus speed setting, their connection pins are connected to the reset signal lines of the motherboards, to allow the low state feature setting selection signals to trigger resets. Thus, a processor that invariantly supports the first bus speed setting, regardless of whether the processor has a processor core that monitors the feature selection signal to determine whether the first or the second bus speed setting is being selected, will operate with either a motherboard that invariantly supports only the first bus speed setting or a motherboard that variantly supports either one of the bus speed settings, when attached to such a motherboard that invariantly supports only the second bus speed setting. Additionally, a processor that variantly supports either one of the bus speed settings will operate with any one of the three types of motherboards, i.e. motherboards that invariantly support only the first bus speed setting, motherboards that variantly support either one of the bus speed settings, and motherboards that invariantly support only the second bus speed setting. When attached to a motherboard that variantly supports either one of the bus speed settings, the combination operates with the second bus speed setting. Accordingly, there is provided an apparatus for ensuring feature compatibility and communicating feature between process and mother boards comprising: (a) a motherboard having a first pin for conveying a feature setting selection signal for a feature, wherein the first pin is connected to internal circuitry of the motherboard in a manner as herien discribed (b) a processor attached to the motherboard, the processor having a second pin corresponding to the first pin for conveying the feature setting selection signal, wherein the second pin is connected to. internal circuitry of the processor in a manner that is as herien discribed hew oupporte4-by-4be processor, said pin connections being complementary to allow the apparatus to operate if the processor and the motherboard support the feature in a compatible manner, and to fail safely if the processor and the motherboard support the feature in an incompatible manner. Accordingly, there is also provided a method for ensuring feature compatibility and communicating feature between processors and motherboards comprising the steps of: (a) connecting a first pin of a processor to internal circuitry of the processor in a manner dependent on how the processor supports a feature; (b) connecting a second pin of a motherboard to internal circuitry of the motherboard in a manner dependent on how the motherboard supports the feature, said support dependent manners of pin connections being complementary to each other; and (C) attaching the processor to the motherboard, thereby allowing the processor and the motherboard to operate with each other if they support the feature in a compatible manner, and allowing the processor and the motherboard to fail safely if they support the feature in an incompatible manner. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will be described by way of exemplary embodiments, but not limitations, illustrated in the accompanying drawing in which like references denote similar elements, and in which: Figure 1 illustrates one embodiments of the present invention for providing feature compatibility between processors and motherboards. DETAILED DESCRIPTION OF THE INVENTION In the following description, various aspects of the present invention will be described. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some or all aspects of the present invention For purposes of explanation, specific numbers and configurations are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well known features are omitted or simplified for clarity. Referring now to Figure 1, wherein three exemplary processors 10a - lOc and three exemplary motherboards 12a - 12c are shown. Exemplary processors 10a- 10c and exemplary motherboards 12a - 12c are esuipped to be feature compatible for an exemplary system bus speed feature in accordance with the present invention. In other words, any one of exemplary processors 10a - lOc may be attached to any one of exemplary- mothsrboards 12a - 12c, notwithstanding their differences in the manner in which the system bus speed feature is supported. In combinations that are compatible, the attached processors lOa, lOb, or lOc and motherboards 12a, 12b or 12c will operate with cash other, and in combinations that are incompatible, the combinations will be allowed to fail safely. No manual intervention, switches, or jumpers are required, as they are in the prior art. The exemplary system bus speed feature includes a first exemplary system bus speed feature setting of 66MHz and a second exemplary system bus speed feature setting of 100MHz. A bus speed selection signal having a low state and a high state is employed to select the bus speed settings, with the low state selecting the 66MHz bus speed, and the high State selecting the 100MHz bus speed. .For the illustrated embodiment, processors lOa, lOb, and 10c include processor cards 15,15b, and 15c having processor cores 14a, 14b. and 14c attached thereon respectively. Processor core 14a invariantly supports the system bus speed feature at 66MHz. Furthermore, processor core 14a does not monitor the bus speed selection signal to confirm that indeed the 66MHz system bus speed is the appropriate system bus speed to be employed. Processor cores 14h and 14c viuiantly support cither the 66MHz or the 100MHz system bus speed. Moreover, processor cores 14b and 14c support monitoring of the bus speed select signal to determine; whether the 66MHz or the 100 MHz bus speed is to be employed However, for one or more design/packaging reasons, processor lOb is to be packaged to invariantly support the 66MHz system bus speed. The impact of this design/packaging consideration will be explained more fully below. Each of processor cards 15a -15c includes an identical male edge connector 16a - 16c having a .system bus speed selection pin 18a - 18c for conveying the bus speed selection signal, even though processor core l4a supports the system bus speed feature in an invariant manner, and does monitor the signal. The exact nature of the reasons are unimportant. Accordingly, pin 18a is not coupled to processor core 14a. while pins 18b and 18c are coupled to processor corss 14b and 14c respectively. Additionally, in accordance with the present invention, pin 18a is coupled to ground 20a to drive the bus speed selection signal to the low state. Similarly, in view of the design/packaging consideration, pin 18b is further coupled to ground 23b to drive the bus speed selection to the low state. Pin 18c is further coupled to pull-up resistor 20c to pull the bus speed selection signal to the high state. The purpose of these additional couplings will be explained in more detail below. Motherboards 12a and 12c invariantly support the system bus speed feature at 66MHz and 100MHz respectively, whereas motherboard 12b variantly supports the system bus speed feature at either 66MHz or at 100MHz. Motherboard 12b includes variable clock 22b that is equipped to generate clock pulses for the system bus at either 66MHz or at 100MHz. Each of motherboards 12a - 12c includes an identical female edge connector 24a - 24c, having a system bus speed selection pin 26a- 26b, even though motherboard 12a and 12c support the system bus speed feature in an invariant manner. Since female edge connectors 24a - 24c are identical, and so are male edg: connectors 16a - 16c, each of processor lOa - lOc may be attached to any of motherboards 12a - 12c. System bus speed selection pins 26a - 26b of female edge connectors 24a - 24c correspond to system bus speed selection pins 18a- 18c of male edge connectors 16a - 16c. In accordance with the present invention, pin 26a of motherboard 12a is coupled to ground to drive the bus speed selection signal to the low state, while pin 26b of motherboard 12b is coupled to variable clock 22b to provide the bus speed selection signal as a clock select signal to variable clock 22b. Pin 26c is coupled to a reset signal line with a low state control signal (RESET#) on the reset signal line denoting a reset stale for motherboard 12c, thereby allowing a low state bus speed selection signal to trigger a reset. Thus, when processor10a (which invartantly supports the system bus speed feature at 66MHz, with its processor core 14a operating independent of the system bus selection signal) is attached to motherboard 12a (which also invariantly supports the system bus speed feature at 66MHz), the combination will operate with the system bus speed of 66MHz as expected. For this combination, the state of the bus speed selection signal is immaterial, as both processor lOa and motherboard 12a operate independent of the bus speed selection signal. However, the bus speed selection signal is driven to the low state by both processor 10a and motherboard 12a. When processor lOa is attached to motherboard 12b (which variantly supports the system bus speed feature at either 66MHz or 100MHz), the combination will also operate with the 66MHZ system bus speed. By advantageously grounding phi 18a of processor lOa, the system bus selection signal is driven to the low state. The low state system bus selection signal is in turn conveyed to variable clock 22b, selecting the 66MHz system bus speed. Furthermore, when processor 10a is attached to motherboard 12c (which invariantly supports the system bus speed feature at 100MHz), the combination will fail safely. By advantageously grounding pin 18a, the bus selection signal is driven to the low state. The low state bus selection signal is conveyed to the reset signal line, triggering a reset for motherboard 12c, and molding motherboard 12c in the reset state. When processor lOb (which invariantly supports the system bus speed feature at 66MHz, with its processor core lOb monitoring the system bus speed select on signal) is attached to motherboard 12a (which invariantly supports the system bus speed feature 65MHz), the combination will piroperly operate with the 66MHz system bus speed. The bus speed selection signal is driven to the low state by both processor lOb and motherboard 12a, selecting the 66MHz system bus speed. When processor lOb is attached to motherboard 12b (which variantly supports the system bus speed feature at either 66MHz or 100MHz), the combination will operate with the 66MHz system bus speed, as expected The has speed selection signal is driven to the low state by processor 1Ob and conveyed to variable clock 22 b, selecting the -56MHz system bus speed. When processor lOb is attached to motherboard 12 c (which invariantly supports the system bus speed feature at 100MHz), the combination will fail safely, as in the combination of processor lOa and motherboard ] 2c. By advantageously grounding pin 18a, the bus selection signal is driven to the low state. The low state bus selection signal is in turn conveyed to the reset signal line, triggering a reset for motherboard 12c, and holding motherboard 12c in the reset state. When processor 10e (which varitntly supports the system bus speed at either 66 MHz or 100MHz, with its processor core 14c monitoring the system bus selection signal) is attached to motherboard 12a (which invariantly supports the system bus speed feature at 66MHz), the combination will properly operate with the 66MHz system bus speed, due to the grounding of pin 26a Motherboard 12a drives the bus selection signal to the low state, selecting the 66MHz system bus speed for processor lOc, When processor 10c is attached to motherboard 12b (which variantly supports the system bus speed feature at either 66MHz or 100MHz), the combination will operate with the 100MHz system bus speed, as expected. By advantageously coupling pin 18c to pull-up resistor 20c, processor lOc pul.s the bus speed selection signal to the high state. The high state bus speed selection signal is in turn conveyed to variable clock 22b, selecting the 100MHz system bus speed. Finally, when processor lOc is attached to motherboard 12c (which invariantly supports the system bus speed feature at lOOMHz), the ccmbinadon will properly operate with the 100MHz system bus speed, since the reset state of motherboard 12c is unaffected by the high state system bus selection signal, which was pulled high by virtue of pin 18c being advantageously connected to pull-up resistor 20c. However, if appropriate, motherboard 12c may assert RESET# to place itself in the reset slate. In summary, by virtue of the present invention, any one of processors 10a- lOc can be attached to any one of motherboards 12a • 12c. These combinations designed to work with each other will work as expected. The incompatible combinations will fail sifely. None of the above desirable results require special sockets, special slots, special form factors, keys, marual intervention, switches and/or jumpers, as would be required by the prior art. While the feature compatibility of the present invention has been described in tenas of the above illustrated embodiment, those skilled in the art will recognize that the invention is not limited to the embodiment described The present invent on can be practiced with modification and alteration within the spirit and scope of the appended claims. In particular, the present invention may be practiced with other features and/or feature settings. Particular examples of other features include but are not limited to transaction protocols, timing parameters, and architectural attributes. Accordingly, the description is to be regarded as illustrative instead of restrictive on the present invention. Thus, a method and apparatus for ensuring feature compatibility and communicating feature settings between processors and motherboardS has been descrlbed. WE CLAIM: 1. An apparatus for ensuring feature compatibility and communicating feature between processors and motherboards comprising: (a) a motherboard having a first pin for conveying a feature setting selection signal for a feature, wherein the first pin is connected to internal circuitry of the motherboard in a manner as herein described; and (b) a processor attached to the motherboard, the processor having a second pin corresponding to the first pin for conveying the feature setting selection signal, wherein the second pin is connected to internal circuitry of the processor in a manner as herein described, said pin connections being complementary to allow the apparatus to operate if the processor and the motherboard support the feature in a compatible manner, and to fail safely if the processor and the motherboard support the feature in an incompatible manner. 2. The apparatus as claimed in claim 1, wherein the said feature has a first and a second feature setting, and the feature setting selection signal has a low and high state for selecting the first and the second feature settings respectively. 3. The apparatus as claimed in claim 2, wherein The said processor has a processor core that invariantly supports the feature at the first feature setting, and operates independent of the feature setting selection signal, and the second pin is exclusively connected to ground to drive the feature setting selection signal to the low state, 4. The apparatus as claimed in claim 3, wherein the said motherboard invariantly supports the feature at the first feature setting; and the first pin is connected to ground to drive the feature setting selection signal to the low state, allowing the processor to operate with the motherboard at the first feature setting. 5. The apparatus as claimed in claim 3, wherein the said motherboard variantly supports the feature at either the first or the second feature setting; and the first pin is connected to a feature select input on the motherboard for the feature, allowing the processor to operate with the motherboard at the first feature setting. 6. The apparatus as claimed in claim 2, wherein the said processor has a processor core that variantly supports the feature at either the first or the second feature setting, and the processor core monitors the feature setting selection signal, and the second pin is connected to the processor core and to ground to drive the feature setting selection signal to the low state. 7. The apparatus as claimed in claim 6, wherein the said motherboard invariantly supports the feature at the first feature setting; and the first pin is connected to ground to drive the feature setting selection signal to the low state, allowing the processor to operate with the motherboard at the first feature setting. 8. The apparatus as claimed in claim 6, wherein the said motherboard variantly supports the feature at either the first or the second feature setting; and the first pin is connected to a feature select input on the motherboard for the feature, allowing the processor to operate with the motherboard at the first feature setting. 9. The apparatus as claimed in claim 2, wherein the said processor has a processor core that variantly supports the feature at either the first or the second feature setting, and the processor core monitors the feature setting selection signal, and the second pin is connected to the processor core and to pull-up resistor to pull the feature setting selection signal to the high state. 10. The apparatus as claimed in claim 9, wherein the said motherboard invariantly supports the feature at the first feature setting; and the first pin is connected to ground to drive the feature setting selection signal to the low state, allowing the processor to operate with the motherboard at the first feature setting. 11. The apparatus as claimed in claim 9, wherein the said motherboard variantly supports the feature at either the first or the second feature setting; and the first pin is connected to a feature select input on the motherboard for the feature, allowing the processor to operate with the motherboard at the second feature setting. 12. The apparatus as claimed in claim 9, wherein the said motherboard invariantly supports the feature at the second feature setting; and the first pin is connected to a reset signal line of the motherboard, wherein a low state signal on the reset signal line denotes a reset state of the motherboard, allowing the processor to operate with the motherboard at the second feature setting, and allowing the motherboard to fail safely in the event the processor is replaced by an incompatible processor, which invariantly supports the feature at the first feature setting instead. 13. The apparatus as claimed in claim 7, wherein the motherboard invariantly supports the feature at the first feature setting; and the first pin is connected to ground to drive the feature setting selection signal to the low state. 14. The apparatus as claimed in claim 2, wherein the motherboard variantly supports the feature at either the first or the second feature setting; and the first pin is connected to a feature select input on the motherboard for the feature. 15. The apparatus as claimed in claim 2, wherein the motherboard invariantly supports the feature at the second feature setting; and the first pin is connected to a reset signal line of the motherboard, wherein a low state signal on the reset signal line denotes a reset state of the motherboard. 16. The apparatus as claimed in claim 1, wherein the feature is system bus speed, having a first and a second bus speed, and the feature setting selection signal is a bus speed selection signal having a low and a high state for selecting the first and the second bus speeds respectively. 17. An apparatus substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.

Documents:

3581-del-1997-abstract.pdf

3581-del-1997-claims.pdf

3581-del-1997-correspondence-others.pdf

3581-del-1997-correspondence-po.pdf

3581-del-1997-description (complete).pdf

3581-del-1997-drawings.pdf

3581-del-1997-form-1.pdf

3581-del-1997-form-13.pdf

3581-del-1997-form-19.pdf

3581-del-1997-form-2.pdf

3581-del-1997-form-3.pdf

3581-del-1997-form-4.pdf

3581-del-1997-form-6.pdf

3581-del-1997-gpa.pdf

3581-del-1997-petition-137.pdf

3581-del-1997-petition-138.pdf