text: the present invention now will be more fully described with reference to the accompanying drawings , in which illustrative embodiments of the invention are shown . this invention may , however , be embodied in many different forms and should not be construed as limited to the embodiments set forth herein ; rather , these embodiments are provided so that this disclosure will be thorough , complete , and will fully convey the scope of the invention to those skilled in the art . like numbers may refer to like elements and process steps throughout . referring to fig1 , which illustrates an exemplary computer system 100 upon which a tool to validate the correctness and use of data during the design of a semiconductor product as disclosed herein , could be installed and / or used . computer system 120 is illustrated as a networked computer system that includes one or more client computers 122 , 124 and 130 such as workstations coupled through a network 128 to a server 126 . server 126 could also be a personal computer , a workstation , a midrange computer , or a mainframe computer . while shown here as a point - to - point connection , computers 122 and 124 need not be coupled to server 126 directly , but may be coupled to yet another network which in turn is connected to server 126 . network 128 represents any type of networked interconnection including but not limited to local - area , wide - area , wireless , and public networks such as the internet or an intranet , and any number of routers and hubs connected in between , e . g ., a local - area network to a wide - area network to the internet through a series of routers and / or other servers . any number of computers and other devices may be networked through network 128 , e . g ., multiple servers , hand - held devices , etc . for the purposes of the invention , computer 130 may represent practically any type of computer , computer system , or other programmable electronic device , including a client computer similar to computers 122 , 124 of fig1 , a server computer , e . g ., similar to server 126 of fig1 , a portable computer , an embedded controller , a hand - held device , etc . computer 130 may be coupled in a network 128 as shown in fig1 or may be a stand - alone device . computer 130 will hereinafter also be referred to as a computer although it should be appreciated that the term “ computer ” may also include other suitable programmable electronic devices capable of allowing a chip designer to use the r ules e ngine . with reference to fig2 wherein the method and apparatus of correctly generating shells and of validating the correctness of the data throughout the design process for a semiconductor product as disclosed herein is installed as an application on computer 230 . computer 230 typically receives a number of inputs and outputs for communicating information externally . for interface with a user or operator , computer 230 typically includes one or more user input devices 236 , 237 , e . g ., a keyboard 136 and / or mouse 140 of fig1 , a trackball , a joystick , a touchpad , and / or a microphone , among others , and one or more output devices 232 such as a display 142 and / or a printer 144 of fig1 , a speaker , among others . some servers , however , do not support direct user input and output . for additional storage , computer 230 may also include one or more storage devices 148 of fig1 , e . g ., a floppy or other removable disk drive , a hard disk drive , a direct access storage device , an optical drive , e . g ., a cd drive , a dvd drive , etc ., and / or a tape drive , among others , that may be connected directly or other storage 246 that may be connected through a storage area network ( san ) or other network 228 . furthermore , computer 230 may include an interface connected to one or more networks 228 , e . g ., a local - area network , a wide - area network , a wireless network , and / or the internet , among others , to permit communication of information with other computers 122 , 124 coupled to the network 128 . it should be appreciated that computer 230 typically includes suitable analog or digital interfaces between processor 240 and each of the components as is known in the art . computer 230 typically includes at least one processor 240 coupled to a memory 242 . processor 240 may represent one or more processors or microprocessors and memory 242 may represent the random access memory ( ram ) devices comprising the main storage of computer 230 , as well as any supplemental levels of memory such as cache memories , nonvolatile or backup memories , programmable or flash memories , read - only memories , etc . in addition , memory 242 may be considered to include memory storage physically located elsewhere in computer 230 , e . g ., any storage capacity used as a virtual memory , e . g ., as stored on a mass storage device 246 coupled to computer 230 with a san or on another computer coupled to computer 230 via network 228 . computer 230 may operate under the control of an operating system 250 such as a unix - based , linux - based , or windows - based operating system , as is known in the art , but is not so limited by the particular operating system , or indeed need not be under the control of any operating system . operating system 250 typically executes various computer software applications , components , programs , objects , modules , etc ., such as an executable program 252 , etc . although the tools and libraries 260 for developing an integrated circuit may be in memory 242 , they need not be . the processor 240 may access the tools and libraries 260 , the required data , other various applications components , programs , objects , modules , etc ., resident on one or more processors in another computer coupled to computer 230 via a network 228 , e . g ., in a distributed or client - server computing environment whereby the processing to implement the functions of the correct shell generation tool may be allocated to multiple computers over a network . in general , the program or method steps which cause a computer to validate correct data during the design of a semiconductor product , whether implemented as part of an operating system or a specific application , component , program , object , module , or sequence of instructions , will be referred to herein as the r ules e ngine . the r ules e ngine typically comprises one or more instructions that are resident at various times in various memory and storage devices in a computer , and that , when read and executed by one or more processors in a computer network , cause that computer to perform the steps necessary to execute steps or elements embodying the various aspects of the invention . while the invention has and hereinafter will be described in the context of fully functioning computers and computer systems , those skilled in the art will appreciate that the various embodiments of the invention are capable of being distributed as a program product in a variety of forms and that the invention applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution . computer program code for carrying out operations of the present invention may execute entirely on the user &# 39 ; s computer , partly on the user &# 39 ; s computer , as a stand - alone software package , partly on the user &# 39 ; s computer and partly on a remote computer or entirely on the remote computer . in the latter scenario , the remote computer may be connected to the user &# 39 ; s computer through a network 128 , for example , the internet using an internet service provider . examples of signal bearing media include but are not limited to recordable type media such as volatile and nonvolatile memory devices , floppy and other removable disks , hard disk drives , optical disks , e . g ., cd - roms , dvds , etc ., among others , and transmission type media such as digital and analog communication links . one input to the r ules e ngine is the application set . an application set is , inter alia , a description of the platform and several shells that make the platform useful to a chip designer . viewing fig3 , a platform 310 is a partially manufactured semiconductor device in which the wafer layers up to the connectivity layers have been fabricated . the platform 310 comprises a base semiconductor wafer from , e . g ., silicon , silicon - on - insulator , silicon germanium , gallium arsenide , other type ii , iiii , iv , and v semiconductors , etc . and is a piece of semiconductor material into which blocks or hardmacs have been diffused into the semiconductor layers . diffusing a semiconductor wafer to create a hardmac simply means that during fabrication of the wafer layers , transistors or other electronic devices have been particularly arranged in the wafer layers to achieve specific functions , such as diffused memory 320 - 328 , 330 - 338 , data transceiver hardware such as i / o phys 340 - 346 , clock factories including phase - locked loops ( plls ) 450 , control i / os 352 , configurable input / output ( i / o ) hardmacs 354 , 356 ; each of the hardmacs have an optimum arrangement and density of transistors to realize its particular function . the platform further comprises an area of transistor fabric 360 for further development of the platform 310 using a suite of generation tools , each of which may incorporate the r ules e ngine as described herein . transistor fabric 360 is an array of prediffused transistors in a regular pattern that can be logically configured by the suite of generation tools herein to achieve different functions . a cell refers to the personalization of the interconnect layers that instantiate the logic gates of the transistor fabric . a memory compiler ( not shown ) may have compiled some blocks of diffused memory 320 - 338 for specific sizes , timing requirements , connections , etc . the placement of these hardmacs , compiled memories , and the reserved areas of the transistor fabric 360 have been situated to achieve the desired timing and performance both within the platform and for the platform 310 to connect externally . one of skill in the art will appreciate that the platform 310 shown in fig3 is only one example of a platform and its components . different platforms may contain different amounts and arrangements of transistor fabric , different amounts of diffused and / or compiled memories , both fixed and configurable i / o blocks , clocks , etc . depending upon the purpose of the final integrated chip . for instance , if the final chip is intended to be a communication and / or network integrated circuit , the periphery of the platform may contain many i / o hardmacs that have been fixed as phys and / or that can be configured differently from one another . likewise , if the final integrated chip is intended to be a specialized microprocessor then it may not have as many i / o hardmacs or configurable i / o , and more or less diffused registers and memories . the point is that there are different platforms for different semiconductor products . the platform 410 , moreover , optionally may include the contact mask and some of the fixed higher layers of connectivity for distribution of power , ground , and external signal i / o . the platform definition is a detailed listing of the physical resources features available on the platform , such as the area and availability of transistor fabric , the i / o and memory available , the requirements of the hardmacs , the cost of the platform , the ideal performance that can be expected of the platform , the expected power consumption , and other functional requirements . for memory elements , the platform definition may include , inter alia , details of : ( a ) area and physical placement of the memory array and its interface / connection pins ; ( b ) bit width and depth ; ( c ) organization , e . g ., numbers of read / write ports , bit masking ; ( d ) cycle time ; and ( e ) power estimates . for i / o elements , the platform definition may provide , inter alia , the types of i / o , the i / o drive strength , etc . for clock elements , the platform definition provides the frequencies at which the platform may operate , the duty cycle , etc . other details of the platform definition may include the configuration of , the transistor fabric and the diffused and compiled elements , the status of the logic , the required control signals and the features enabled by the control signals , whether any element undergoes testing , the location and the number of the elements on the platform , etc . the platform and its definition are of little use to a designer needing to develop a functional integrated circuit , so several representations of the diffused resources of the platform are needed ; shells are these representations . shells are the logic and other infrastructure that makes the platform useful as a design entity , and the r ules e ngine described herein is preferably used to generate these shells . the platform description is input to circumscribe all other generated parameters and other user input to make the platform useful to design a semiconductor product . using the r ules e ngine and a suite of other generation tools , a chip designer can integrate her / his customer &# 39 ; s requirements with the platform &# 39 ; s resources and definition to verify and synthesize designs generated by each tool , insert clocks , create the test interconnects , and then integrate the designs together to create a complete design . the resultant design , moreover , is a qualified netlist with appropriate placement and routing amongst the existing resources and for external connections to a board . to create a customized chip , all that is needed is a small set of remaining masks to create the interconnections between the preplaced elements . there are a number of shells used by a designer to integrate her / his customer &# 39 ; s requirements using a particular platform description , and depending upon the designer &# 39 ; s particular task ; one or more of these shells can be used . while the following description is not intended to be limitative , it is nonetheless , fairly representative of the infrastructure necessary to use the platform and create a functional semiconductor product from the platform . these shells comprise : the rtl shells , the documentation shell , the verification shell , the synthesis shell , the static timing analysis shell , the manufacturing test shell , the floorplan shell , and the rtl qualification shell . the rtl shell provides a logical description of the platform , and the generated or user resources . the documentation shell may be considered the functional description of the resources . the verification shell is the functional verification description , and the synthesis shell may be thought of as the generation description . the static timing analysis shell is the timing description , the manufacturing test shell is the test description , and the floorplan shell is a location description of the platform resources . an additional perspective of these shells may be obtained by abstracting the semiconductor product as modules based upon the source of the rtl and the function of the logic , such as shown in fig4 . one of skill in the art will understand that these shells are not necessarily generated according to this or any other abstraction ; that is to say , a generated verification shell or any other shell may have aspects in one or more of these modules and that the shells are not necessarily generated in the order of or limited to the following modules . the information is presented to show the complexity and the interconnectedness of the shells with each other and with the modules throughout the semiconductor platform . the generated module 410 preferably comprises the shells generated by a suite of generation tools for i / o , memory , clocks , or may be derived from other known semiconductor design tools such as described in copending united states patent applications , commonly owned by the assignee herein and hereby incorporated by reference in their entireties : ser . no . 10 / 435 , 168 filed 8 may 2003 entitled a utomation of the d evelopment , t esting , and r elease of a f low f ramework and m ethodology to d esign i ntegrated c ircuits , ser . no . 10 / 318 , 792 filed 13 dec . 2002 entitled f lexible t emplate h aving e mbedded g ate a rray and c omposable m emory for i ntegrated c ircuits ; ser . no . 10 / 318 , 623 filed 13 dec . 2002 entitled a utomated s election and p lacement of m emory d uring d esign of an i ntegrated c ircuit : ser . no . 10 / 334 , 568 filed 31 dec . 2002 entitled p lacement of c onfigurable i nput / o utput b uffer s tructures d uring d esign of i ntegrated c ircuits : ser . no . 10 / 335 , 360 filed 31 dec . 2002 entitled a s implified p rocess to d esign i ntegrated c ircuits : ser . no . 10 / 465 , 186 filed 19 jun . 2003 entitled d esigning and t esting the i nterconnection of a ddressable d evices of i ntegrated c ircuits , and ser . no . 10 / 713 , 492 filed 14 nov . 2003 entitled f lexible d esign for m emory u se in i ntegrated c ircuits . the generated module 410 may include some preplaced , timed , and proven components , such as one or more clock generators , system controllers and reset logic , test controllers , and / or analog serializers / deserializers ( serdes ) hardmac components . the generated module 410 has connectivity requirements to the various modules and their components through bus logic 418 to the several modules along an internal bus 480 and / or external bus 482 . bus logic 418 may include arbiters , multiplexers , decoders , etc . to manage the connectivity and , if necessary , the address translation and register / memory coherence schemes . surrounding the generated module 410 is the user module 420 . logic from the customer for whom the integrated circuit is designed comprises the user module 420 and may include prefabricated logic and hardware such as cores , hardmacs , ios , registers 422 , etc . also included in the user module 420 may be a list of memories and / or registers having tie - offs , i . e ., the memories and / or registers that will not be used for data flow and may thus be allocatable for performance enhancing features such as control status registers , etc . the user module 420 also provides input into the r ules e ngine described herein . the fixed module 430 is created with the application set and thus encompasses the fixed resources and the shells pertaining to these fixed resources of the application set . the fixed module 430 and its accompanying shells provide the template upon which the customer &# 39 ; s requirements will be built and are input into the r ules e ngine described herein . the fixed module 430 may be as simple as logic signals directly connected to external chip i / os , or it may be more complex logic upon which the user module 420 and the generated module 410 can build . for example , shells of the fixed module 430 could include the complete infrastructure to support a pci bus controller 432 , 432 a including all the connections to external i / os and / or a ddr / sram memory controller , a processor subsystem 436 , 436 a , etc . the r ules e ngine herein accepts the shells of the fixed module 430 and then further facilitates matching and binding the memories , register blocks , any cores 436 in the fixed module to the top module 450 , such as matching protocols and correctly binding the correct i / o hardmacs phys 452 , such as an xgxs to support data transfer at gigabit ethernet speeds , or a mw spi - 4 core . the core module 440 encompasses the fixed module 430 and the user module 420 and may be described as the correct and proven logic interfaces connecting them with each other and with the top module 450 . the top module 450 contains the logic and supporting shells for the hardmacs and configured logic towards the periphery of the platform for outside communication . the top module 450 thus contains the i / o blocks and i / o diffused areas and any registers associated with the hardmac and configurable i / os . the instantiated i / o blocks that use the top module 450 may include the plls , the i / o netlists of which a nand tree is a part , test logic , and lock detect circuits , etc . a number of input tables describing the interconnect templates are used by the r ules e ngine to integrate the bus masters of 452 a 454 a , 456 a , 458 a , 462 a of their respective top module components 552 , 554 , 556 , 558 , 562 with the application set and the rest of the design . these top module components may include a jtag tap controller 456 , an ethernet interface 452 , a cpu connection interface 454 , and / or an eeprom interface 458 , etc ., each of which may require special consideration when inputting associated parameters . fig5 is a simplified flow chart of a method 500 of generating correct shells for the platform and modules described in fig3 and 4 . in fig5 , the process 500 begins at step 510 whereby the application set and user requirements of the user module and its shells are automatically input to the t emplate e ngine . at step 512 , the r ules e ngine and t emplate e ngine read the parameters of the application set and / or the user &# 39 ; s specification , for example , the names of signals , names of inputs / outputs , etc ., that will be used to generate a shell ( s ). at this time the input parameters of the shells are checked to ensure their correctness and completeness at step 514 , preferably by the c orrect d ata e ntry and the r ules e ngine . if the input parameters are not correct , then the process immediately loops back to step 512 giving the user an opportunity to enter correct shell parameters . if , however , the parameters for the shell are correct , the user selects a shell , such as an rtl , simulation , documentation shell , to generate at step 516 . then , at step 518 , the shell ( s ) is / are automatically generated e . g . by allocating the appropriate data to its respective template , such as described the t emplate e ngine . after the shell is generated , then different paths of fig5 are taken depending upon the particular shell . for instance , if the correctly generated shell is an rtl and / or simulation shell , then at step 522 , the rtl is compiled . note , that at this time , the rtl language and syntax will be correct and need not be checked . then , the rtl is then simulated as in step 524 to determine how the actual signals will transfer from register to register , and the process returns at step 585 . after generation of the correct documentation shell 530 , the process returns . the correct timing shell 540 will undergo timing analysis at 542 and return . the correct manufacturing test shell 550 generated by the tool as described herein can be used to generate manufacturing vectors at step 552 which will be tested at step 554 . the correct synthesis shell 560 will be run at step 562 , and the correct floorplan shell 570 will generate a floorplan as in step 572 . the r ules e ngine as described herein ensures that the parameters input into it and other generation tools are correct , complete and comply with any rules and constraints put upon them . fig6 is one of the flowcharts of the r ules e ngine that assures correct input and distribution of correct data into the specifications used to generate the shells for each component . fig6 addresses the rules and directives for phase lock loops ; fig7 a and 7b present a flow of the process whereby parameters and specifications of clocks are confirmed for correctness by the r ules e ngine . fig8 is a flowchart of the rules and directives for the memories of a semiconductor product . fig9 a through 9b deal with the complexity of checking the input / output buffers and signals for correctness by the r ules e ngine during the generation of shells . one of skill in the art will of course realize that the concept and the rules and directives herein are not limited to plls , clocks , memories , and i / o buffers , but can apply to complex hardmacs that have register spaces , such as processors . the figures are understandable knowing the nomenclature and conventions . an arrow connecting a block to itself or other blocks means that the values or names in the block are consulted to obtain new values or names and / or are changed as a result of a change in the first block . the numbers around a box indicate the order of evaluation . and notion of xcy means that x is conditional on y being true whereas the notation xcyf means that x is conditional on y being false . there are preferences for the syntax for signal names , as outlined in the t emplate e ngine , filed concurrently here within , but which will be reiterated here for convenience . signal names preferably contain a - z , a - z , 0 - 9 , _ , and [ ], and start with a - z or a - z . multiple underscores ______ tend to be burdensome and uninterpretable given the language and syntax and are therefore discouraged . numbers are allowed only between brackets , such as [ 12345678 ]. for floating point numbers , it is preferred that they do not contain exponential notation and be less than one million . integers are preferably numeric characters with a maximum number of nine characters . following is a list of some of the parameters , data that could be included in the original data from the application set and / or the user &# 39 ; s specification and / or generated during the process of chip design . the physical location on the package where a signal will be located . the side of the die where the signal is located . possible values are : left , right , this field indicates how the bump is used . possible values are : power , signal , name of the signal associated with the package location . the name chosen must comply with all signal name naming conventions . refer to naming conventions . name of the signal associated with the package location . you must choose a name that complies with all signal naming conventions . refer to naming conventions . this field indicates the type of i / o buffer that is diffused onto the slice . diffused i / o this field indicates the maximum capability of the i / o buffer . possible values for this if the buffer type require a vref , this field identifies the signal name used as a voltage reference for the i / o buffer . if the buffer type is bz i / o , this field indicates if the buffer type requires a vref , this field identifies the signal name used as a voltage reference for the i / o buffer . if the buffer type is bz i / o , this field indicates this field indicates the direction of the i / o . it will automatically be filled in if the i / o direction is in , out , or blank . if the i / o direction is inout , possible values are in , this field indicates the direction of the i / o . it will automatically be filled in if the i / o direction is in , out , or blank . if the i / o direction is inout , possible values are : in , this field indicates what type of configurable i / o buffer is being used . this field indicates what type of configurable i / o buffer is being used . type of component to which the signal is being routed . the possible values are : the name of the component to which that signal will connect . a drop - down list is name of the port on the component to which that signal connects . a drop - down list type of component to which the signal is being routed . the possible values for component types are based on what component type ( plafform ) was chosen . this field states if the signal is to be used for test purposes . possible values are : no use this field to add any additional information about the primary i / o . a requirement specifying the minimum time in nanoseconds that the data must be the name of the clock used to capture data on input ports . a drop - down list is generated from the list of all clocks defined in the clock specifications table . a requirement specifying maximum time in nanoseconds between the sourcing clock the name of the clock used to launch data on output ports . a drop - down list is generated from the list of all clocks defined in the clock specifications table . the name of the clock component . this must be a unique name . refer to the naming the mode of clock output for a clock factory element . this defines how many outputs the clock factory element needs . possible values are : nominal , nominal this field is computed . the value of this field is the result of the value in the oscillator source frequency field divided by the value in the divider field . the oscillator source for the clock component . possible values are : primary i / o , the logical name of the oscillator source . if the oscillator source type is primary i / o , then this field is the name of a primary i / o . if the oscillator source type is recovered clock , then this field is the name of a ucm port . if the oscillator source type is pll , then this field is the name of a pll . the name of the reset source for the clock component . if the name does not match any primary i / o name , then a ucm port is created with the reset source name . the output frequency of the pll . this value is determined from the feedback used to derive the output frequency . this is required to achieve the output the logical name for the memory component . each memory component must have a a value that indicates if the logical memory component should be created from r - cell only or if the tool should choose between r - cell and diffused elements . a value of true , forces the tool to create a memory logical component from r - cells . a value of false , allows the tool to choose between diffused and r - cells when creating a logical memory component . this field can only contain a true or false the number of ports for the logical memory component . possible values are : 1 defines how flip - flops will be placed in memory access paths to assist in timing . this field indicates if error protection logic should be built and the memory size adjusted accordingly for the logical memory component . possible values for this field specifies the exact diffused memory element ( s ) to use when constructing a logical memory . this field does not apply if the memory component is built using r - cells . for diffused memories , if the user does not select a physical reference , the tool as a result of using the t emplate e ngine and c orrect d ata e ntry with the r ules e ngine herein , component types picked by a user or customer match the component type of application set or the user module or not at all . the terms in parenthesis , platform and user , such as on the charts as in fig9 a vref ( platform ) or in fig9 b component port ( user ), indicate whether the component is part of the application set as defined herein earlier , i . e ., a partially manufactured semiconductor device that can be further developed by the user into a customized semiconductor product , or whether the component is added by the user in finalizing her / his integrated circuit design . of course , an intermediate purpose of the t emplate e ngine and the r ules e ngine is to generate the shells that are necessary and facilitate the design and manufacture of semiconductor products . examples of some of the rules of the r ules e ngine are that at the time of generating the shells , the method herein checks that the port per instance must be unique for single ended buffer types . the port can be duplicated only for differential buffer types . uniqueness of the i / o names is checked , as well as assuring that the ports for the core module and the user core module are unique and are defined . single bit buses , moreover , are either not allowed or discouraged . the rules pertaining to each resource will be further explored . fig6 applies the rules and directives applicable to the parameters of the specifications table of phase lock loops ( pll ). at step 602 , a pll , of which there may be more than one on the application set , or in the customer &# 39 ; s requirements is given a name . the r ules e ngine herein applies four checks to the block labeled pll name 602 : first , the name must be unique and non - null as indicated along path 604 . if the name is unique and non - null , then the name is checked to determine if it is unique at the core module , the user module , the fixed module , and the generated module ( see fig4 and discussion herein ) along path 606 . below is a basic checklist of some of the ports in the modules to consider : the core module components , ports of the generated modules , the input signals and output signals of the generated modules , such as the test signals , the reset source name , the oscillator source name , companion enable , i . e . the alternate clock and select signal for the companion enable , and the reset pulse source whose signal could end with _rst_pulse_src_n . the output signals of the generated module could include the test signals , the clock name , and the reset name . the fixed module has its ports , input signal names and output signals names ; as does the user core module . one of skill in the art will further recognize that there may be proprietary name rules , checks and requirements to be included in these figures and conventions . if the name is unique within these modules , i . e ., condition 2 is true , then , at 3 along path 608 , the oscillator source name ( 750 in fig7 a ) must be updated , if the pll is used as the source of oscillation . at 4 , paths 610 and 612 , the component names of the platform and user ( 970 and 1010 in fig9 a ), respectively , must be updated . block 632 of fig6 refers to a physical reference indicating that the pll is a diffused resource ; the r ules e ngine will check that the name of the physical reference is non - null , unique , and complies with signal base syntax , either conventional and / or proprietary , see e . g , columns 632 of fig1 and 1330 of fig1 . block 630 refers to the type of pll , and example of which is given in column 1328 of fig1 . of course , they may be different types of pll , each given a unique index as in block 660 and perhaps each having their own rules , consistency checks , etc . the range and naming conventions of the output frequency 614 is checked along path 616 so the value chosen for the output frequency is within an allowable range . then at path 618 , the feedback divider 624 may be changed along path 628 to maintain the reference frequency 626 . if , however , given an output frequency or a change in the output frequency 614 , the feedback divider and the output frequency cannot be maintained , as in path 620 , then the reference frequency 626 needs to be changed . if the output frequency 614 has changed , oscillating source frequency ( 760 in fig7 a ) is updated along path 622 . referring now to the fig7 a and 7b , which applies rules and directives for the correct clock naming and actions . an index 710 is maintained ; there usually is more than one clock name or clock , sometimes up to sixty or more for a communications semiconductor product , in the design so the index helps to keep track . at block 720 , a clock name is checked at loop 604 , to validate that the name is unique , non - null , and compiles with the conventions and / or requirements for signal names . in loop 606 , the name is checked to determine it is unique at the core module level indicating that name is not duplicated in the user module , the fixed module , and the generated module . then , at path 722 , if the name of the clock is changed , then the change may also propagate and affect the alternate clock 732 which must also have a unique , non - null , name compliant with naming syntax conventions and proprietary requirements . if , however , a user performs a row delete operation on the clock specifications table , as in fig7 b path 734 , then the r ules e ngine determines if the alternate clock 732 should also be deleted or is otherwise affected . at block 730 a change in the divider &# 39 ; s value updates the frequency 780 along path 628 . also affecting frequency 780 is a change in the oscillator source frequency 760 to maintain an appropriate range . the oscillation source frequency 760 must comply with floating point syntax , as along path 604 . note that along path 622 , a change in the output frequency of the connected pll ( 614 in fig6 ) also affects the oscillation source frequency 760 . block 750 refers to the oscillation source name , which preferably is non - null and complies with signal base syntax . if the oscillator source 750 is a pll ( as in 602 of fig6 ), or a primary input / output ( i / o ) signal , or a recovered clock , the r ules e ngine herein verifies the name also exists in the table for plls and i / os . the name of the oscillator source 750 must be unique throughout the models , as along path 606 . also affecting the oscillator source name 750 is the oscillator source type 770 in fig7 b ; a change in the oscillator source type 770 ripples along path 752 to the oscillator source name 750 . path 752 of the r ules e ngine chooses a name for the oscillator source name 750 depending upon whether the source is a pll , a primary i / o , or a recovered clock . likewise , a user &# 39 ; s change of the signal name ( 1024 in fig9 b ) can affect the oscillator source name 750 , as in path 758 , depending upon the present value of the signal name . if the name exists as the oscillator source name 750 and if the oscillator source type 770 is a primary i / o signal , then the oscillator source name 750 is set to a new value and the rules engine applies this change to a clock specification table similar to the i / o specification table of fig1 and 12 . referring to fig7 b , the oscillator source type 770 is given a name which along path 772 must be unique , non - null . if , moreover , a pll has not been defined in the pll specification , the oscillator source type 770 cannot be a pll ; similarly , if no primary i / os have been defined in the i / o specifications , then the oscillator source type 770 cannot be a primary i / o . the changes of the oscillator source type 770 also affect the oscillator source frequency 760 along path 762 , and affect the oscillator source name 750 , as discussed . the reset signal is named as in block 790 of fig7 b and its name must be non - null and comply with the signal name base syntax and industry and / or company conventions . the reset source name 790 is connected to the signal name defined by the user ( 1024 in fig9 b ) such that if the user changes or creates a name for the reset signal coming from the reset source 790 , the r ules e ngine also changes the reset source name 790 . these rules and directives are only examples of what might be implemented when designing and instantiating a clock for a semiconductor product . a table may be constructed with all the parameters ; if a rule or directive limits the choices for a particular clock , those limited parameters will be offered , or grayed out , or otherwise made to be not available during the correct entry of the parameters . fig8 is an example of how the rules and directives and influences in specifying memory in a semiconductor product can be applied . an index 810 of the memory usage is created and a memory is given a name in 820 which must be unique , non - null , and comply with any syntactic requirements and conventions . the number of words in a memory are input in block 830 and the bit width of each word is input at block 850 and the r ules e ngine herein automatically verify the numbers of words and bit width are valid , i . e ., the depth and width of the words are allowable and the input value complies with the syntax requirements , such as integer base . along paths 832 and 852 , once the depth and width are validated , the physical reference 860 to the diffused memory of platform resources are updated . the physical reference 860 will be checked at 604 to see if it satisfies the requirements of other fields , such as words 830 , bits 850 , ports 874 , and if so , the physical reference 860 is allowed . along path 842 , if memory is configured from the transistor fabric , labelled r - cell 840 , the rules engine will consult and update the resource viewer of fig1 by checking if there are any rcells available as in block 1348 and then updating block 1346 to indicate that the some of the transistor fabric has been allocated , as in block 1346 . fig9 a and 9b present the rules and directives for the i / o specifications to incorporate the platform resources with the user &# 39 ; s requirements to achieve a semiconductor product . the parameters can be conveniently categorized into user requests and platform resources . such requests and resources presented in fig9 are not intended to be limitative but rather , are examples of platform resources and user &# 39 ; s requests . reference voltage of the platform 910 and the reference voltage specified by the user 920 are two such resources and requests . the r ules e ngine checks the reference voltages of both or either the platform 910 and the user 920 to determine if the name complies with syntactic requirements , as along path 604 . in this instance , an empty string for the value of the voltage is acceptable . in a preferred embodiment , the reference voltage is always derived from an external i / o source , so the r ules e ngine confirms that the i / o buffer type is correct for a reference voltage . the r ules e ngine further verifies that the names and values also exist in the signal name blocks of the platform 1020 along path 932 and that the new value exists in the signal name block of the user 1024 along path 922 , respectively . blocks 930 , 1020 , and 1024 refer to i / o signal names and , in particular , the signal names of the bondout , the platform , and those given by the user , respectively . the names of signals of the slice specification are read into block 930 signal name ( bondout ) and becomes the default names for the signal name ( platform ) 1020 along path 932 . if the name of the i / o signal is changed when further developing the platform , then that name may be propagated to signal name ( user ) 1024 along path 1022 . thus the signal name ( bondout ) 930 may be considered the default , and a chip developer can change the signal names at the platform level at signal name ( platform ) 1020 and / or at the user level at signal name ( user ) 1024 . in any event , when the i / o signal name is defaulted from the signal name ( bondout ) 930 or defaulted from the signal name ( platform ) 1020 , the signal name in signal name ( user ) 1024 is also reflected in the reset signal name ( 790 in fig7 b ) along path 792 if the signal is a reset signal , or is reflected in changes in the oscillator source name fig7 a along path 758 . the signal names at the various levels , i . e ., the signal name ( bondout ) 930 , signal name ( platform ) 1020 , and signal name ( user ) 1024 are checked by the r ules e ngine to ensure that the name complies with industry , proprietary , syntactic conventions and requirements . the r ules e ngine may also verify that the i / o signal names at any of these levels , i . e ., bondout , platform , user , represent that the signal may be dedicated to test usage such as for jtag , test insertion , tree optimization , etc . if , moreover , any of these i / o signals are intended to be used for reference voltage signals at either the platform or user level , changes in the names or other parameters will be propagated to the vref ( platform ) along path 914 and / or vref ( user ) along path 922 . by default , the r ules e ngine loads all i / o buffers into diffused i / o type 940 , but if there is a label to state that an i / o buffer is configurable , then that buffer is also loaded into the configurable i / o type ( platform ) 950 and the configurable i / o type ( user ) 1040 . configurable i / o type ( platform ) 950 may be configured as an i / o buffer type for a configurable i / o type ( user ) along path 954 or remain as an configurable i / o type ( platform ) 950 . the parameters associated with the i / o types 940 and / or 1040 include the i / o direction of which that i / o buffer is capable , i . e ., can the i / o buffer be inout , in , or out . the rules engine further is aware that some of the parameters are determined by the type of i / o buffer ; an i / o buffer type is determined by , inter alia , its electrical characteristics , such as voltage levels , differentiality , etc . examples of different types include hstl , sstl , lvds , pect , etc . thus , the actual use , e . g ., whether in or out or inout , of a diffused i / o buffer type 940 is recorded in i / o use ( platform ) 1054 along path 944 and / or in i / o use ( user ) block 1058 along path 942 . similarly , the actual i / o platform use of an i / o configurable buffer is indicated along path 1052 in block i / o use ( platform ), and the actual i / o use of a user &# 39 ; s configurable i / o 1040 is indicated along path 1044 in i / o use ( user ) 1058 . if a test feature is selected in test usage ( platform ) 1066 for an i / o diffused buffer 940 , the r ules e ngine verifies that the i / o buffer allows tests for a matching bump is differential signal pair . similarly if the i / o buffer is input or output for a differential signal , the r ules e ngine confirms that there are two rows ( bumps ) right next to each other and identifies the polarity . if an i / o buffer is selected for an i / o signal in a major power plane , the r ules e ngine verifies that that the voltage level of the signal is compatible with the power plane . also represented in fig9 a and 9b are checks for the components used by the platform and the user . each component is characterized by its type , its name , and its port . if a platform implements a component , that component type ( platform ) of block 960 is checked first to determine if the component type exists in the design along path 604 . the i / o buffer and the component type must be compatible , e . g ., if the i / o buffer , whether diffused or configurable , is to be connected to a pll , or an i / o hardmac , such as gigablaze or hyperphy , then the r ules e ngine verifies compatibility . if the component type is part of the user module , the r ules e ngine verifies that this component type is allowable , is not a test signal , or a major power plane , such as along path 962 . if all these conditions on path 604 associated with block 960 , then along path 962 , the value may also be set in the component type ( user ) block 990 ; otherwise if used by the platform its name is tracked in block 970 along path 972 for the same parameters . the r ules e ngine and the t emplate e ngine are used to create instantiated and formatted shells used in the creation , the design , and the manufacture of semiconductor products . data is obtained from a data base , preferably using the enumerated lists or input checking , such as described in c orrect d ata e ntry , that ensures correct data . the t emplate e ngine specifically addresses issues such as the syntax of the language and the structures common in hardware design used in semiconductor integrated circuit . the t emplate e ngine and the r ules e ngine described herein are part of a builder tool that automatically manages slice resources from an application set and builds rtl code for memories , i / os , and clocks of a semiconductor product . in one embodiment , the builder tool uses input tables of specifications to assign i / os , clocks , plls , and memories ; other input techniques include notebooks of circuit diagrams , graphical representations of the architecture , etc . the builder tool can be installed as an application on any client or any server accessible through a network to a client computer . first , a user might select to create a design and then , in the preferred embodiment , a screen of the tool &# 39 ; s selection tables as is shown in fig1 is displayed . as is typical in a networked environment , the r ules e ngine can be applied to multiple data files across a network . in fact , the top module can be completely generated using the builder tool using the r ules e ngine as described herein . logical memories and clocks can be added and / or deleted . to add a logical memory / clock , the designer may click the memories / clocks and select add on a menu bar of a graphical user interface . in one embodiment , a new row will be added to a memory / clocks specifications table . logical memory / clocks may be deleted and upon deletion , the memory / clock will be deleted from its respective memory / clocks specifications table . of course , more than one memory / clock may be deleted at a time by highlighting cells in multiple rows for the memories / clocks to be deleted . bus declarations may be entered easily using the builder tool . a bus is a group of input / output ports that share a common signal name . an bus can be declared by specifying a signal name having an individual bit in square brackets representing a starting index , for example , bus_name [ 5______ ]. a user could simply highlight a range of ports , assign a common base name , and then from a starting index , a user could simply increment or decrement the ports on that bus . optionally , a user can manually change each port or use other copy / paste techniques . in one embodiment of the t emplate e ngine , one bit buses are not allowed ; indices are contiguous , and the least significant bit is zero . a screen shot of a resource viewer is shown in fig1 . the resource viewer may list the technology and the name of the semiconductor platform . the technology of the chip , typically referring the gate length of the transistors , may be presented at 1302 , and the name slice at 1304 . the resource viewer 1300 has several windows which list the i / o resources 1306 available for development , the pll resources 1324 available for development , the i / o resources of the coreware 1334 , i . e ., the hardmacs and / or logical functions that are available for design , instantiated , and ready for use , and the memory resources 1344 . each of these windows may have a pull - down window , hypertext links , or other known method to expand the view into the windows for a more complete lists of the factors and parameters affecting a particular resource . for i / o resources 1306 , the resource viewer 1300 may display how many signal i / os have been used , and how many are available . for phase locked loops ( plls ) 1324 , hardmacs 1334 , and diffused memories 1344 , the resource viewer 1300 may display if a specific component is used or unused 1326 , 1358 , the type of component , and the physical reference of any diffused i / o components , e . g ., 1330 , 1354 . for logical memories to be configured from the transistor fabric , the resource viewer may display how much transistor fabric has been used 1346 and how much is available 1348 . in some embodiments , there may be a limitation to the amount of transistor fabric that can be utilized for memory , e . g ., only 25 percent . an example of how to use a partially completed i / o table is shown in fig1 ; a designer may wish to edit a signal . the designer first locates the signal to be edited in a row 1504 of the table and may change the name in the signal name ( user ) 1024 column if needed . then , in the config io type ( user ) 1040 column , the user may select the cell she / he wishes to configure and either selects an appropriate i / o buffer from the drop - down list or enter one in accordance with c orrect d ata e ntry . the r ules e ngine will verify that the selected buffer is at the same voltage level as all other buffers on the same power segment , i . e ., the buffer name indicates the voltage level of the buffer . for bidirectional buffers , i / o use ( platform ) 1054 which is indicated as inout , the designer may select how the i / o is going to be used in the i / o use ( user ) 1058 column . under the component type ( user ) 990 column , the chip designer may select the user module ( um ) option from the drop - down list which may appear in the cell . in accordance with the rules engine herein , if a chip designer ( user ) attempts to enter an illegal connection , an error dialog box will appear and the attempted modification may be ignored . any of these methods of editing the contents of the specifications tables will invoke the algorithms that implement the r ules e ngine to ensure that the modifications , additions , deletions are constantly updated and continuously valid throughout the design . using the clock specifications table , a user may configure a clock from a pll by first adding a clock to the table and in the osc source type column , select or entering a pll . in the osc source name column , the user is requested to change the name to the desired pll and , if desired , to change the clock name in the clock name field . the value in the divider column is changed and will automatically change the clock frequency . then the reset source is set ; if the user wants the reset to come from a primary i / o , she / he is requested to enter the name from the signal name ( user ) column into the reset source column . while the description provides embodiments of the invention , the embodiments are considered illustrative and by way of example only and are not intended to be limitative . rather , the invention is as claimed is :