fig2 depicts a system - level block diagram of how the passive smart card adapter and a smart card interface with a host controller . the controller 10 is integrated into a pc platform , for example , laptop pc . as an example , the pc may be configured as shown , with the controller 10 operating to detect and control one or more expansion device cards that are inserted into socket a 12 and / or socket b 14 . it will be understood that the controller 10 of present invention is adapted with the appropriate logic to drive pc cards as well as smart cards . the pc system typically includes a processor 26 and a data bus 20 . “ north bridge ” logic 24 provides communication between the processor 26 and the bus 20 . the controller 10 , of the present invention is likewise adapted to communicate with the bus 20 . in this example , the bus 20 is a pci bus , however , any bus technology can be incorporated into the controller &# 39 ; s logic . to complete the picture , “ south bridge ” logic is provided for external bus communications , for example , legacy devices ( isa bus architecture ), etc . south bridge and north bridge logic are well known in the art . power ic chip 28 supplies the correct voltages ( as determined by the card type inserted into socket a or b ) to the pins of the pc card connector . once the type of card is detected ( based on the pc card definitional table of fig5 discussed below ), chip 28 supplies the appropriate voltage for that card type . in one embodiment , the present invention provides a passive smartcard adapter 18 which is configured to be inserted into either socket a 12 or socket b 14 , which are in turn configured as either pc card type i / ii / iii — type socket interface . the passive adapter 18 of this embodiment includes appropriate connector 84 and passive circuit 86 . the smart card 16 inserted into the passive smart card adapter 18 also includes physical contacts 88 to interface with the physical connector 84 of the adapter . pinout arrangements 84 and 88 of the adapter and smart card are dictated by the smart card specification , for example pc / sc compliant smart card specification that meets iso 7816 electrical specifications and t = 0 , t = 1 protocols . in this embodiment the use of an adapter 18 permits smart card readability and operability without retooling the pc case to include a specific smart card socket . alternatively , the pc can include a smart card slot 14 ′ as shown in fig2 . in this alternative embodiment , the logic 86 and connector 84 are , of course , provided internally within socket 14 . referring now to fig3 a more detailed block diagram of the integrated controller 10 is depicted , showing those logic portions directed to smart card detection and operability . in this example , the controller 10 includes smart card sensing logic 30 a and 30 b , smart card multiplexer ( mux ) logic 32 a and 32 b , smart card reader logic 34 a and 34 b and interface logic 36 a and 36 b . it should be noted at the outset that fig3 depicts only the logic associated with smart card and passive smart card adapter detection and operability , and it should be understood that controller 10 includes additional logic ( not shown ) to permit detection and operation of conventional pc card &# 39 ; s . conventional pc card controllers detect the type of card inserted into a slot using a set of card detection pins , cd 1 and cd 2 , and a set of voltage sense pins vs 1 and vs 2 . the coupling combinations between these pins ( with reference to ground ) indicate to the appropriate logic which type of card has been inserted into the socket . for example , as shown in the table of fig5 the coupling combination of cd 1 , cd 2 , vs 1 and vs 2 determine whether the pc card inserted is a 16 - bit pcmcia card or a 32 - bit cardbus card . moreover , as is shown in the table , this combination also determines the driving voltage for the particular type of card . for example , 3 . 3 v , 5 v , x . x v and y . y v . in the last two rows of the table of fig5 it is to be noted that the listed combinations of cd 1 , cd 2 , vs 1 and vs 2 are reserved in the pc card specification . the present invention utilizes one of these reserved combinations of cd 1 , cd 2 , vs 1 and vs 2 , and additionally uses a status change signal , stschg , to indicate whether a smart card has been inserted into the slot ( either directly , or via an adapter ). the status change signal is preferably used in the present invention since this signal is not utilized during the detection process for conventional pc card cards , and is only used once the card type is known . thus , in one sense , the smart card sensing logic 30 a shown in fig3 can be viewed as a state machine that determines the type of card inserted into a socket . to that end , and referring to fig4 a state machine representation of the card sensing logic 30 a of fig3 is depicted . as is shown , the card sensing logic 30 a accepts as inputs cd 1 , cd 2 , vs 1 , vs 2 and status change ( labeled 40 , 42 , 44 , 46 and 48 , respectively ). in accordance with the reserved arrangement of cd 1 , cd 2 , vs 1 , vs 2 as shown in fig5 and the addition of the status change signal , the state machine 30 a determines the appropriate logic 32 a for communicating with the given type of card . for example , certain combinations of cd 1 , cd 2 , vs 1 , vs 2 ( as indicated in fig5 ) will dictate that the card inserted into the socket is either a 16 - bit pc card or a 32 - bit cardbus pc card . accordingly , the state machine 30 a will activate the appropriate logic 50 or 52 for the given card type . it should also be noted that the particular voltage of the inserted card is also determined using the combination of these four pins . extending the capabilities of conventional pc card controllers , the present invention also monitors the stschg pin to determine if a smart card or a passive smart card adapter has been inserted into the socket , and likewise activates the appropriate logic 54 to communicate with the smart card , for example , logic 32 a as shown in fig3 . to determine the states of cd 1 , cd 2 , vs 1 , vs 2 and stschg , the card sensing logic 30 a can produce , for example , a pulse train signal on selected ones of these pinouts , and by monitoring the signal on one or more of the other pins ( with respect to ground ), it can then be determined the card type inserted into the socket . the smart card sensing logic 30 a and 30 b operate to detect both a smart card or a passive smart card adapter and pc cards , based on the table in fig5 . the pin assignments shown in fig5 are designated by the pc card specification , and are conventional pin assignments for these signal lines . the identity of the card is determined by the values of the voltages of columns 1 - 4 , i . e ., cd 2 , cd 1 , vs 2 and vs 1 . both smart card and passive smart card adapter detection operates by utilizing the reserved combinations of these pins , plus the use of an additional pin , for example , stschg signal line . the concept is summarized in the table of fig7 b . this table shows the pins used to detect pc cards , smart cards and passive smart card adapter cards . the signal column for a smart card or passive smart card adapter detection includes one of the reserved areas for cd 1 , cd 2 , vs 1 and vs 2 , as shown in the last two rows of table of fig5 . it should be noted that although the figures depict the use of signal line stschg ( which is provided by the conventional pc card specification ), the present invention , generally , could use any pin in the pc card specification that is unused during the card detection sequence . in other words , from a timing perspective , certain signal lines in the pc card specification remain unused during the card detection process . the present invention utilizes one ( or more ) of these signal lines , in conjunction with the reserved combination of cd 1 , cd 2 , vs 1 , and vs 2 , to effectuate smart card or passive smart card adapter detection . thus , the figs . represent only one of many examples for the use of an additional signal pin that could be used for smart card detection . a flow chart 60 of the card - type detection process is depicted in fig6 . for clarity , the corresponding reference numerals of the logic to detect and operate pc card , smart card and passive smart card adapter cards ( as shown in fig2 and 3 ) are omitted . initially , the detection logic seeks the presence of cd 1 , cd 2 , vs 1 , vs 2 , and stschg 62 . if not present , or otherwise unavailable , it is assumed the no card has been inserted into a socket , and thus the card detection signals ( cd 1 and cd 2 ) are blocked 64 . once a card is inserted , the detection logic monitors the falling edge of cd 1 or cd 2 66 . this is dictated by the pc card specification for determining the presence of a card . once a card is detected , the detection logic of the present invention toggles cd 1 , cd 2 , vs 1 , vs 2 , and stschg to determine the type of card inserted 68 . toggling , as cited above , can be in the form of a pulse train signal , or other toggling signal . the detection logic proceeds by polling cd 1 , cd 2 , vs 1 , vs 2 , and stschg in the following manner . first , the logic determines if vs 1 and cd 2 are tied to ground 70 . if not , it is known that a 16 - bit pcmcia card or 32 - bit cardbus card is inserted 72 , as indicated by the table of fig5 . if yes , the logic determines if vs 2 and cd 1 are tied together 74 . if this is not the case , again it is known that a 16 - bit card or 32 - bit cardbus card is inserted 76 , as indicated by the table of fig5 . if it is determined that cd 1 and stschg are tied together 78 , then it is determined that a smart card or a passive smart card adapter is present . either the passive smart card adapter is inserted into the socket , or a smart card is inserted directly into a smart card socket 82 . another feature of the present invention is to provide an integrated controller circuit 10 , which can be directly integrated with current pc card controller logic . conventional pc card controller logic is an ic package that is mounted directly on the motherboard , which has 208 pins , and each of these pins is assigned by the pc card specification . another feature is to provide a controller 10 that can directly replace conventional controllers , without having to reconfigure pin assignments , add additional pin configurations , alter the motherboard , or change the tooling required . to that end , and referring to the table of fig7 a , the controller 10 of present invention includes both conventional , legacy interface card signals and smart card signals . as is shown in this table , the same pins ( leftmost column ) used to interface with conventional 16 and 32 cards are likewise used to interface with the smart card . thus , no additional pins are required . referring again to fig3 if a smart card is detected into a socket , logic 30 a or 30 b communicates with and enables logic 34 a or 34 b , to enable smart card readability . logic 34 a and 34 b enable the socket mux logic 32 a or 32 b , so that the socket ( a or b ) can communicate with the cardbus / pci controller logic 36 a or 36 b , which communicate with the pci bus 20 ( via pci interface 38 ). as should be understood , the smart card logic 30 a , 30 b , 34 a and 34 b of the present invention directly interfaces with the mux logic 32 a and 32 b and communicates with bus interface controllers 36 a and 36 b using conventional pc card communication protocols . if a conventional card is inserted into a socket ( socket a or b ), then conventional logic ( not shown ) incorporated into the controller 10 activates mux 32 a and 32 b and communicates with bus interface controllers 36 a and 36 b using conventional pc card communication protocols . to facilitate direct integration with conventional pc card logic sets , the present invention controls a predetermined number of pre - assigned pins to effectuate smart card communication . for example , as shown in fig7 a , pins 17 , 51 , 58 , 47 , 32 , gnd , 18 , 16 and 40 , as specified by the pc card standard , are utilized by the present invention to operate both smart cards and pc cards . therefore , no extra pins are required by the controller 10 to effectuate smart card operability . in operation , once the smart card has been detected ( as described above with reference to fig3 - 6 ), logic 34 a or 34 b reassigns the operability of the pc card pins noted in fig7 a to effectuate smart card readability . the signal assignments , set forth under the smart card signal column of fig7 a , are the required signals to read smart cards . the table and fig7 a is included as a lookup table in the controller 10 of the present invention to operate pc cards . likewise , the tables of fig5 and fig7 b are included as lookup tables in the controller 10 for the detection of pc cards and smart cards . to this end , and view the logic sets 30 a and 30 b as a state machine ( shown in fig4 ), the state machine compares the input signals to the lookup tables of fig5 and 7b to couple the appropriate logic to the card . those skilled in the art will recognize that cd 1 , cd 2 , vs 1 and vs 2 comprise card detect and voltage select signals , respectively , as specified by the conventional pc card signal specification . in the tables of fig5 a and 7 b , and the flowchart of fig6 the nomenclature used for these signal lines includes , for example , cd 1 #, cd 2 #, vs 1 #, vs 2 #, etc ., which are the formal names for these conventional signal lines . however , it should be apparent that the use of cd 1 , cd 2 , vs 1 and vs 2 are shorthand versions of these formal names , and may be used interchangeably . thus , it is evident that there has been provided an integrated smart card controller and smart card detection process that satisfies the aims and objectives stated herein . it will be apparent to those skilled in the art that modifications are possible . for example , although the present invention has been described with reference to detection and operation of smart cards , the present invention is equally adapted for the detection and operation of any type of expansion cards , in addition to conventional pc cards . other modifications are possible . for example , it may be desirable to include a software lock on the operability of the smart card logic shown herein . accordingly , the logic depicted in fig3 can include an enable bit , which selectively turns on and off smart card detectability and operability . to that end , and referring to fig6 the smart card detection process may alternatively include the step of determining if an enable bit is enabled , and if cd 1 and stschg are tied together 84 . if this is not the case , the smart card the logic will not detect the presence of a smart card . this feature of the present invention permits , for example , manufacturers to offer smart card compatibility as an upgrade option , while still integrating the core logic of the controller 10 . those skilled in the art will recognize additional modifications , and all such modifications are deemed within the scope of the present invention , only as limited by the appended claims .