Patent Publication Number: US-8122165-B2

Title: On-demand power supply current modification system and method for an integrated circuit

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to the field of integrated circuits. In particular, the present invention is directed to an on-demand power supply current modification system and method for an integrated circuit. 
     BACKGROUND 
     Advancements in technology and manufacturing capabilities change the operational characteristics of a semiconductor device. While these changes include improvements in overall performance and processing capabilities, they also include corresponding increases in, e.g., power density requirements. Unfortunately, changes in the power density of a semiconductor device oftentimes increase faster than the structural changes to the device necessary to meet the increased power needs. Indeed, physical constraints to the overall device may limit these structural changes. In one example, although certain improvements to a semiconductor device may include an increase in power density, its ability to meet the increased power requirements is limited by its input/output capabilities. 
     SUMMARY OF THE DISCLOSURE 
     In one embodiment, a circuit for selectively connecting an integrated circuit to a plurality of external paths, the plurality of external paths including a first signal path and an external power supply, the circuit including a second signal path internal to the integrated circuit; a power network internal to the integrated circuit; and an input/output element configured to switch amongst a plurality of modes including a first mode and a second mode, the first mode connecting the first signal path to the second signal path via the input/output element, the second mode connecting the power network to the external power supply via the input/output element. 
     In another embodiment, a circuit for selectively connecting one or more external paths with an integrated circuit, the one or more external paths including a first signal path, the circuit including a second signal path internal to the integrated circuit; a power network internal to the integrated circuit; a first means for switching amongst a plurality of inputs including the second signal path and the power network; a second means in electrical communication with the first means, the second means for switching amongst a plurality of external paths including the first signal path and the power supply, wherein when the first means is connected to the second signal path, the second means is connected to the first signal path such that the second signal path and the first signal path are in electrical communication, and when the first means is connected to the power network, the second means is connected to the external power supply such that the power network and the power supply are in electrical communication. 
     In still another embodiment, a method of modifying the power supply current to an integrated circuit, the integrated circuit having an input/output pin, the method including determining a power supply requirement from the operation of the integrated circuit; and alternately connecting the input/output pin to an external signal path or an external power supply as a function of the power supply requirement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein: 
         FIG. 1  is a schematic diagram of one embodiment of a circuit for connecting elements internal to an integrated circuit with elements external to the integrated circuit. 
         FIG. 2  is a schematic diagram of another embodiment of a circuit for connecting elements internal to an integrated circuit with elements external to the integrated circuit. 
         FIG. 3  is a schematic diagram of yet another embodiment of a circuit for connecting elements internal to an integrated circuit with elements external to the integrated circuit. 
         FIG. 4  is a flow diagram of an optional algorithm implemented in an embodiment of a circuit, such as the circuit illustrated in  FIGS. 1 ,  2  and  3 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates one embodiment of a system  100  for selectively connecting integrated circuit  105  to elements external to the integrated circuit. These external elements include, but are not limited to, a signal path, a power supply, a test device, and any combinations thereof. In the present example, the external elements include an external signal path  110  and an external power supply  115 . 
     Integrated circuit  105  may be an electronic circuit, or combination of electronic circuits, that perform functions important to electronic design. Examples of an integrated circuit (e.g., integrated circuit  105 ) include, but are not limited to, a micro-processor, a micro-controller, an application specific integrated circuit (ASIC), an application specific standard product (ASSP), a customer specific standard product (CSSP), a mixed signal IP, and any combinations thereof. In the present example, integrated circuit  105  is an integrated circuit chip having internal elements that require communication to and from external elements, such as those external elements discussed above. Examples of an internal element include, but are not limited to, a signal path, a power network, and any combination thereof. Here, these internal components include an internal signal path  120  and an internal power network  125 . An internal signal path (e.g., internal signal path  120 ) may be any path that electrically communicates one or more data elements as is known by those of ordinary skill. A power network (e.g., power network  125 ) distributes power to portions of integrated circuit  105 . 
     System  100  also includes an input/output element  130 . An input/output element  130  provides selective electrical connection between the elements internal to integrated circuit  105  and the elements external to integrated circuit  105 . In one example, input/output element  130  provides this selective connection by switching between a plurality of modes. In one mode, input/output element  130  electrically connects external signal path  110  with internal signal path  120 . In another mode, input/output element  130  electrically connects power supply  115  with power network  125 . 
     System  100  further includes a controller  135  that communicates with input/output element  130 . Controller  135  controls the switching of input/output element  130 , such as, for example, by switching input/output element  130  from one mode to another mode. In this example, controller  135  may be associated with an optional algorithm  140  that instructs the switching of input/output element  130 . Algorithm  140  may include a set of instructions that control the switching input/output element  130 , as described in more detail below. In one example, controller  135  may be hardware based on executing logic for controlling input/output element  130 . 
     Examples of a controller include, but are not limited to, a processor, a flip-flop state machine with control logic, and any combination thereof. In the present example, controller  135  is positioned on or within integrated circuit  105 . It is contemplated, however, that alternative configurations of controller  135  may provide that it be located external to integrated circuit  105 . In still other configurations of system  100 , controller  135  can be incorporated within input/output element  130 , such as, for example, within the circuit structure of input/output element  130 . 
       FIG. 2  illustrates another embodiment of a system  200  for selectively connecting external elements (an external signal path  210  and a power network  215 ) to internal elements (internal signal path  220  and power network  225 ). The internal and external elements are connected to an input/output element  230  that is controlled via a controller  235  and an optional algorithm  240 . In the present example, input/output element  230  includes a switching device  245  and a switching device  250 . A switching device (e.g., switching devices  245 ,  250 ) may be any electronic device that can selectively switch between one or more inputs and/or one or more outputs. Examples of a switching device include, but are not limited to, a pass gate multiplexer, a relay, a switching circuit, and any combinations thereof. 
     Input/output element  230  also includes an electrically conductive wire  255  that can be connected to the internal and external elements via switching device  245  and switching device  250 . In one example, wire  255  may be an input/output pin. The electrical connection of wire  255  can be changed by switching device  245  and switching device  250 . In one aspect, switching device  245  is configured to switch electrical connection of wire  255  between signal path  220  and power network  225 . In another aspect, switching device  250  is configured to switch electrical connection of wire  255  between signal path  210  and power supply  215 . 
     In one implementation of an on-demand system and method, the electrical connection of wire  255  with the various internal and external elements can vary as a function of the operating condition of integrated circuit  205 . A variety of operating conditions may influence the operating mode of input/output element  230 . Examples of an operating condition include, but are not limited to, a high-power condition, a low-power condition, a high signal connectivity condition, a low signal connectivity condition, and any combinations thereof. In one example, as integrated circuit  205  requires less power and/or signal throughput, input/output element  230  (e.g., with instructions from controller  235 ) may switch to a first operating mode. 
     Input/output element  230  may selectively switch between a plurality of operating modes In one mode, switching device  245  electrically connects to internal signal path  220  and switching device  250  electrically connects to external signal path  210 , thereby electrically connecting internal signal path  220  and external signal path  210  via wire  255 . In another mode, switching device  245  electrically connects to power network  225  and switching device  250  electrically connects to power supply  215 , thereby electrically connecting power network  225  and external power supply  215  via wire  255 . 
       FIG. 3  illustrates yet another embodiment of a system  300  for selectively connecting the internal and external elements of an integrated circuit  305 . In this example, system  300  connects external elements (an external signal path  310  and a power supply  315 ), with internal elements (an internal signal path  320  and a power network  325 ). The connection occurs via an input/output element  330  that is connected to a controller  335 , optionally having an algorithm  340 . Input/output element  330  includes a switching device  345  and a switching device  350  that switch the connection of an input/output pin  355  with the internal and external elements. 
     Controller  335  includes electrical devices that allow controller  335  to switch switching devices  345 ,  350 . In one example, controller  335  includes a control I/O  335   a  and I/O arbiter  335   b . Those of ordinary skill will be readily familiar with these devices, as well as other devices, designs and configurations in connection with controller  335  such that they need not be described in any detail herein, other than to the extent necessary to describe how features of the present disclosure may be implemented. Control I/O  335   a  and I/O arbiter  335   b  electrically communicate with switching devices  345 ,  350 , respectively. A plurality of switching devices can be arranged in a manner so as to allow controller  335  (e.g., through control I/O  335   a  and I/O arbiter  335   b  or other electrical configuration) to control all of the switching devices. In the present example, a single input/output pin  370  is used to control switching device  350 . In other examples, multiple pins may be utilized to transfer one or more control signals to one or more switching elements, such as switching element  350 . Although only a single pair of switching devices  350 , 355  is illustrated, it is contemplated that other embodiments of system  300  can include a plurality of pairs of switching devices that are arranged to electrically communicate in a serial relationship, such that a single input/output pin can be used to control the series of switching devices. 
     In this embodiment, system  300  varies the connection of input/output pin  355  with the internal and external elements in accordance with the functional requirements of integrated circuit  305 . As illustrated in  FIG. 3 , controller  335  communicates with a logic element  337  of integrated circuit  305  and controls switching devices  340 ,  345  in response to power supply requirement  365 . A power supply requirement (e.g., power supply requirement  365 ) provides information or instructions to controller  335  about the functional requirements of integrated circuit  305 . These functional requirements can include, for example, a requirement for additional input/output pins to provide increased power and/or a requirement for additional input/output pins to transmit signals between the internal and the external elements. Examples of a power supply requirement include, but are not limited to, a power requirement  365   a,  a signal bandwidth requirement  365   b,  and any combination thereof. 
     Controller  335  responds to one or more of input requirements  365  by switching input/output element  330 . In one example, controller  335  responds to power requirement  365   a  by switching input/output element  330  into a power mode. A power mode allows the transmission of a power signal from the external elements, via input/output pin  355 , to the internal elements. In a power mode, controller  335  connects switching device  350  with power supply  315  and connects switching device  345  with power supply  325 . In another example, controller  335  responds to signal bandwidth requirement  365   b  by switching input/output element  330  into a signal mode. A signal mode allows the bidirectional transmission of a data signal, via input/output pin  355 , between external elements and the internal elements. In a signal mode, controller  335  connects switching device  350  with signal path  310  and connects switching device  345  with signal path  320 . 
     As discussed above, controller  335  can be associated with an algorithm  340  that provides instructions for determining the switching of switching devices  345 ,  350 . In one example, algorithm  340  includes a set of instructions having pre-determined information describing the power requirements and/or the signal bandwidth requirements of integrated circuit chip  305 . In another example, algorithm  340  includes a set of instructions for determining power requirement  365   a  and signal bandwidth requirement  365   b  from input requirement  365  provided by integrated circuit chip  205 . In still another example, algorithm  340  includes a set of instructions for responding to power requirement  365   a  and signal bandwidth requirement  365   b  received from integrated circuit chip  305 . 
     Referring next to  FIG. 4 , and also  FIG. 3 , an example  400  of an algorithm that responds to power requirement  365   a  and/or signal bandwidth requirement  365   b  is illustrated. In this example, algorithm  400  receives an input requirement  405  at Step  310 . As discussed above, input requirement  405  prompts controller  335  to switch input/output element  330 . 
     If, e.g., input requirement  365  is a power requirement  365   a,  algorithm  400  proceeds to Steps  415 - 460 , which instruct controller  335  to switch input/output element  330  into a power mode. At step  415 , algorithm  400  allows any input/output operation in progress at the time the power requirement is received to be completed. Then, at step  420 , algorithm  400  instructs controller  335  ( FIG. 3 ) to disable the input/output and signal this disablement to integrated circuit chip  305 . Next, at steps  425  and  430 , algorithm  400  instructs controller  335  to connect switching device  345  to power supply  315  and switching device  350  to power network  225 . Then, at steps  435  and  440 , algorithm  400  instructs controller  335  to acknowledge the power requirement by signaling to integrated circuit chip  305  and waiting for the completion of the necessary function, as signaled by the power requirement  365   a.  Finally, at steps  445 ,  450 ,  455 , and  460 , algorithm  400  instructs controller to connect switching device  345  to signal path  310 , connect switching device  350  to internal signal path  320  and remove the power requirement acknowledgement. 
     Referring back to  FIG. 3 , an optional implementation of system  300  also includes an optional receiver  375  that may be used in a receiver implementation, discussed in more detail below. A receiver (e.g., receiver  375 ) is known in the art. In addition to receiver  375 , system  300  may include other optional electrical components. The present example, for instance, includes a flush latch  380  that electrically communicates with receiver  375 , as illustrated in  FIG. 3 . Examples of a flush latch include, without limitation, any memory element that can be configured to hold its existing state in one mode, or pass an input state directly to its outputs in a flush mode. This example also includes optional resistors  385   a,    385   b.  Examples of resistors include, without limitation, a pull-up resistor, a pull-down resistor, and any resistor or other device that functions so as to hold a node at a specific level. It can be appreciated that these components are recognized in the art such that they need not be described in any detail herein. 
     In a receiver implementation, system  300  may operate in a signal mode or a power mode. In a signal mode, system  300  switches switching device  345  to electrically connect with receiver  370 . Switching device  350  is switched to electrically connect with signal path  310 . Flush latch  380  is maintained in a flush state. In a power mode, system  300  switches switching device  345  to electrically connect with power network  325 . Switching device  350  is switched to electrically connect with power supply  315 . The value at the input to receiver  375  is set to known signal level (e.g., a voltage level) using resistor  385   a.  Flush latch  380  is maintained in a retain state. 
     Another optional implementation of system  300  includes an optional transmitter  390  that may be used in a transmitter implementation, discussed more below. A transmitter (e.g., transmitter  390 ) is an input/output driver, or any other IC driver circuit known in the art. In a transmitter implementation, system  300  may operate in a signal mode or a power mode. In a signal mode, system  300  switches switching device  345  to electrically connect with transmitter  390 . Switching device  350  is switched to electrically connect with signal path  310 . In a power mode, system  300  switches switching device  345  to electrically connect with power network  325 . Switching device  350  is switched to electrically connect with power supply  315 . Signal path  320  is modified to a known signal level (e.g., a voltage level) using resistor  385   b.  Flush latch  380  is maintained in a retain state. 
     Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention.