Abstract:
An apparatus is used to identify the type of microprocessor assembly mounted on a printed circuit board. A heat sink is coupled to the microprocessor assembly, and a label is coupled to the heat sink. The label has one of a plurality of preselected patterns of optically reflective and non-reflective areas formed thereon, and at least one photodetector is positioned adjacent the microprocessor assembly on the printed circuit board for detecting the preselected pattern.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a method and apparatus for automatically detecting the type of semiconductor device in a circuit, and, more particularly, to a system for automatically identifying the core speed of a microprocessor. 
     2. Description of the Related Art 
     In the semiconductor industry, the speed rating assigned to a semiconductor chip, such as a microprocessor, is determined by testing after the device is manufactured. That is, various microprocessors from the same batch may be rated to operate at different speeds, depending upon the outcome of the testing process. The various speed microprocessors are sorted and sold at different prices, but are otherwise packaged identically, and have the same pin configurations. Accordingly, all of the microprocessors, regardless of their speed, may be installed in the same physical connector on a printed circuit board, such as a motherboard. 
     To insure that the computer system operates the installed microprocessor at its maximum intended speed, it has been conventional to locate jumpers on the motherboard. The jumpers may be manually configured to identify the type of microprocessor installed on the motherboard. That is, the end user is provided with a map to identify how the jumpers should be interconnected to properly identify the microprocessor installed on the motherboard. 
     The manual jumper arrangement is problematic in that the individual installing the microprocessor may be unaware of the need to alter the jumper arrangement, and/or may simply forget to do so. Thus, the installed microprocessor may run at a much slower speed, or may not operate at all. 
     The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, an apparatus is provided for identifying a device mounted on a substrate. The apparatus includes a label coupled to the device and a sensor positioned adjacent the device on the substrate. The label has one of a plurality of preselected patterns formed thereon, and the sensor is capable of detecting the preselected pattern. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which: 
     FIG. 1 is an exploded perspective view of one embodiment of the present invention; 
     FIG. 2 is an assembled end view of the embodiment of FIG. 1; 
     FIG. 3 illustrates a stylized block diagram of one embodiment of the present invention; 
     FIG. 4 illustrates a flowchart of one embodiment of software operating on the microprocessor of FIG. 1; and 
     FIG. 5 depicts one embodiment of reflective markings on a heat sink of FIG. 1 used to identify the type of microprocessor attached thereto. 
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in art having the benefit of this disclosure. 
     Referring now to the drawings, and in particular to FIG. 1, an exploded perspective view of a portion of a motherboard of a computer system  10  is shown. The motherboard  12  is shown with a conventional edge card connector  14  located on a surface thereof. The edge card connector  14  is of the type adapted to receive a microprocessor assembly  16 , which in the illustrated embodiment is a slot  7  package available from Intel Corporation, such as is used with its Pentium II® microprocessor. The microprocessor assembly  16  includes an outer housing  18  with a microprocessor (not shown) mounted to a printed circuit board  19  (see FIG. 2) contained therein and adapted to be physically and electrically connected to the edge card connector  14 . To facilitate the removal of heat from the microprocessor assembly  16 , a heat sink  20  is coupled to a first side wall  22  of the housing  18  of the microprocessor assembly  16 . The heat sink  20  may be coupled to the housing  18  by any of a variety of conventional methods, including but not limited to, gluing, soldering, riveting, bolting, or the like. 
     Accordingly, it should be appreciated that the heat sink  20  extends laterally from the housing  18  and overhangs the motherboard  12  adjacent the edge card connector  14 . Positioned below the heat sink  20  is a plurality of photodetectors  24 . Three photodetectors  24  are shown in the embodiment of FIG. 1; however, the number of photodetectors may be varied as needed to provide a sufficient number of unique combinations to identify all possible speeds of microprocessors that may be inserted into the edge card connector  14 . 
     A reflective/non-reflective strip is coupled to a lower surface of the heat sink  20  in an area generally overlying the photodetectors  24 . FIG. 2 illustrates an end view of the assembled motherboard  12 , better illustrating the location of the reflective strip  26  above and adjacent the photodetectors  24 . Light generated by the photodetectors  24  is reflected/not reflected by the strip  26  in a pattern unique to the speed of the microprocessor installed in the edge card connector  14 . Thus, this unique pattern on the strip  26  is detected to identify the speed at which the microprocessor may be operated. 
     One example of a reflective strip  26  that may be attached to the heat sink  20  to identify the type of microprocessor included within the microprocessor assembly  16  is illustrated in FIG.  5 . The reflective strip  26  includes three areas  28 A,  28 B,  28 C that are positioned adjacent and readable by the three photodetectors  24 . The areas  28 A,  28 B,  28 C may be selectively coated to provide a surface that reflects a substantial portion of the light delivered to it, or absorbs a substantial portion of the light delivered to it. For example, the reflective strip  26  may take the form similar to that of a bar code present on many consumer goods. That is, the areas  28  may be coated to absorb light using a relatively dark ink, such as black, or may be made to reflect a substantial portion of the light by the absence of a dark ink in these areas. The three areas  28 A,  28 B,  28 C may be selectively coated/not coated to provide eight unique codes, and thereby identify eight unique speeds of processor operation. For example, in the embodiment illustrated in FIG. 5, the areas  28 A and  28 B are not coated, while the area  28 C is coated, producing the unique code 001. The number of areas  28  and the number of photodetectors  24  may be varied to accommodate a number of different operating speeds available for the microprocessor assembly  16  that may be installed in the edge card connector  14 . 
     Referring now to FIG. 3, a stylized electrical schematic of one embodiment of the present invention is illustrated. A control circuit  30 , which may be located on the motherboard  12 , the printed circuit board  19 , or within the microprocessor (not shown), controls the operation of a memory device  32 , such as a register, to read the status of the photodetectors  24 . That is, the photodetectors  24  read the pattern of the areas  28 A,  28 B,  28 C from the reflective strip  26  and translate the presence/absence of the reflective areas  28  into logical signals (i.e., zero or one). The identification pattern read from the reflective strip  26  is converted to ones and zeros and stored in the register  32  under operation of the control circuit  30 . Thereafter, the control circuit  30  reads the information contained in the ID register  32  and uses it to set the proper operating speed of the microprocessor assembly  16 . 
     Referring now to FIG. 4, one embodiment of a control strategy implemented within the control circuit  30  is illustrated in a flowchart  49 . It should be appreciated that the control strategy illustrated in the flowchart  49  may be implemented in software, hardware and/or firmware. 
     The control strategy starts at block  50  where the initialization process begins. In particular, at block  52 , the ID register  32  is loaded in response to the delivery of a control signal over a line  34 . That is, light reflected from the areas  28 A,  28 B,  28 C is detected and loaded into the register  32  as a logical one. Similarly, light absorbed by the areas  28 A,  28 B,  28 C is not detected by the photodetectors  24 , and thus a logical zero is loaded into the register  32 . The register  32  is thereafter read by the control circuit  30  over data lines  36 . Finally, at block  54 , the control circuit assists in configuring the core speed for the installed microprocessor (not shown) contained within the microprocessor assembly  16 . 
     It should be appreciated that while the present invention has been disclosed with respect to a reflective strip  26  and photodetectors  24 , it is envisioned that other sensor arrangements may be readily substituted without departing from the spirit and scope of the present invention. For example, it is envisioned that the photodetectors  24  could be replaced by magnetic sensors, such as hall effect sensors, and the reflective strip  26  could be replaced by an arrangement of magnetic/non-magnetic material. 
     The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.