Wordline driver circuit having an automatic precharge circuit

Abstract

The invention is an automatic precharge circuit featuring precharge devices each of which is interposed between a high voltage node, connectable to a supply potential, and a serial node. The precharge devices are gated automatically by a primary predecode signal of a decode portion of the row decoder. Power is conserved since the serial nodes are passively pulled to the supply potential through the precharge devices. The invention increases speed and provides error free wordline selection.

What is claimed is: 
     
       1. A circuit for selecting a wordline, comprising: a) a decode means for generating a primary select signal and a secondary select signal, having active and inactive states, in response to an address, said primary and secondary select signals determining selected and non-selected wordlines;   b) a driving means for driving said selected and said non-selected wordlines to active and inactive potentials respectively in response to said primary and secondary select signals, said driving means having a pass device activated by said secondary select signal having said active state;   c) a serial node electrically interposed between said pass device and the wordline; and   d) an automatic precharge means for charging the serial node to a desired potential, said automatic precharge means actuated by said primary select signal when said primary select signal has a potential which drives said non-selected wordlines to said inactive potential.   
     
     
       2. The circuit as specified in claim 1, wherein said wordline is non-selected in response to said inactive state of said primary select signal. 
     
     
       3. The circuit as specified in claim 1, further comprising a random access memory device having the circuit for selecting a wordline. 
     
     
       4. The circuit as specified in claim 1, further comprising a computer having the circuit for selecting a wordline. 
     
     
       5. A circuit for automatically precharging a serial node, said circuit comprising: a) an output node in electrical communication with the serial node and capable of being driven to active and inactive potentials;   b) a primary select node for accepting a primary select signal capable of having a first and a second potential and for determining a potential of the output node;   c) a pass device electrically interposed between the serial node and the primary select node;   d) a precharge node connectable to a precharge potential; and   e) an automatic precharge device interposed between said precharge node and the serial node, said automatic precharge device having a control input in electrical communication with said primary select node such that when said primary select signal has said first potential said automatic precharge device pulls said serial node toward said precharge potential.   
     
     
       6. The circuit as specified in claim 5, wherein said output node is driven to said inactive potential by said primary select signal having said first potential. 
     
     
       7. The circuit as specified in claim 5, further comprising: a) a latch node in electrical communication with said serial node;   b) monitoring circuitry in electrical communication with said latch node, said monitoring circuitry generating a latch signal at said latch node in response to said inactive potential being on said output node; and   c) latch circuitry in electrical communication with said output node, said latch circuitry latching said inactive potential to said output node in response to said latch signal.   
     
     
       8. A circuit for selecting an active and an inactive wordline at a direction of a primary select signal and a secondary select signal, comprising: a) a primary select node for accepting said primary select signal;   b) a pass device electrically interposed between said wordline and said primary select node, said pass device having a control input, an actuation and a deactuation of said pass device controlled by said secondary select signal at said control input;   c) a serial node electrically interposed between said pass device and said wordline;   d) a precharge node connectable to a precharge potential; and   e) an automatic precharge device interposed between said precharge node and said serial node, said automatic precharge device having a control input in electrical communication with said primary select node, said automatic precharge device actuated in response to said primary select signal when said primary select signal has a value necessary to inactivate said wordline. .Iadd.   
     
     
       9.  A circuit for selecting a wordline, comprising: a) decode means for generating a primary select signal and a secondary select signal, having active and inactive states, in response to an address, said primary and secondary select signals determining selected and non-selected wordlines;   b) driving means for driving said selected and said non-selected wordlines to active and inactive potentials respectively in response to said primary and secondary select signals, said driving means having a pass device activated by said secondary select signal having said active state;   c) a node electrically interposed intermediate said pass device and the wordline; and   d) an automatic precharge means for charging the intermediate node to a desired potential, said automatic precharge means actuated by said primary select signal when said primary select signal has a potential which drives said non-selected wordlines to said inactive potential. .Iaddend..Iadd.10. The circuit as specified in claim 9, wherein said wordline is non-selected in response to said inactive state of said primary select signal. .Iaddend..Iadd.11. The circuit as specified in claim 9, further comprising a random access memory device having the circuit for selecting a wordline. .Iaddend..Iadd.12. The circuit as specified in claim 9, further comprising a computer having the circuit for selecting a wordline.   
     
     
        .Iaddend..Iadd.     A circuit for automatically precharging a node disposed intermediate a pass device and a wordline, said circuit comprising: a) an output node in electrical communication with the intermediate node and capable of being driven to active and inactive potentials;   b) a primary select node for accepting a primary select signal capable of having a first and a second potential and for determining a potential of the output node;   c) a pass device electrically interposed between the intermediate node and the primary select node;   d) a precharge node connectable to a precharge potential; and   e) an automatic precharge device interposed between said precharge node and the intermediate node, said automatic precharge device having a control input in electrical communication with said primary select node such that when said primary select signal has said first potential said automatic precharge device pulls said intermediate node toward said precharge potential. .Iaddend..Iadd.14. The circuit as specified in claim 13, wherein said output node is driven to said inactive potential by said primary select signal having said first potential. .Iaddend..Iadd.15. The circuit as specified in claim 13, further comprising:   a) a latch node in electrical communication with said intermediate node;   b) monitoring circuitry in electrical communication with said latch node, said monitoring circuitry generating a latch signal at said latch node in response to said inactive potential being on said output node; and   c) latch circuitry in electrical communication with said output node, said latch circuitry latching said inactive potential to said output node in   
     
     
        response to said latch signal. .Iaddend..Iadd.16.  A circuit for selecting an active or an inactive wordline at a direction of a primary select signal and a secondary select signal, comprising: a) a primary select node for accepting said primary select signal;   b) a pass device electrically interposed between said wordline and said primary select node, actuation and deactuation of said pass device controlled by said secondary select signal;   c) a node electrically interposed intermediate said pass device and said wordline;   d) a precharge node connectable to a precharge potential; and   e) a precharge control device interposed between said precharge node and said intermediate node, said precharge control device having a control input in electrical communication with said primary select node, said precharge control device actuated to charge said intermediate node from said precharge potential in response to said primary select signal when said primary select signal has a value necessary to inactivate said   
     
     
        wordline. .Iaddend..Iadd.17.  A circuit for selecting a wordline, comprising: a) decode circuitry for generating a primary select signal and a secondary select signal determining selection and non-selection of said wordline in response to an address, each of said signals having an active state and an inactive state;   b) circuitry for driving said wordline to an active or an inactive potential when respectively selected or non-selected in response to said primary and secondary select signals, said driving circuitry including a pass device activated by said secondary select signal having said active state;   c) a node electrically interposed intermediate said pass device and said wordline; and   d) a precharge circuit for charging the intermediate node to a desired potential, said precharge circuit actuated by said primary select signal when said primary select signal has a potential which drives said wordline when non-selected to said inactive potential. .Iaddend..Iadd.18. The circuit as specified in claim 17, wherein said wordline may be non-selected in response to said inactive state of said primary select signal. .Iaddend..Iadd.19. The circuit as specified in claim 17, further comprising a random access memory device including the circuit for selecting a wordline. .Iaddend..Iadd.20. The circuit as specified in claim 17, further comprising a computer including the circuit for selecting a   
     
     
        wordline. .Iaddend..Iadd.21.  A circuit for precharging an intermediate node, said circuit comprising: a) an output node in electrical communication with the intermediate node and capable of being driven to active and inactive potentials;   b) a primary select node for accepting a primary select signal capable of having a first and a second potential and for determining a potential of the output node;   c) a pass device electrically interposed between the intermediate node and the primary select node;   d) a precharge node connectable to a precharge potential; and   e) a precharge initiation device interposed between said precharge node and the intermediate node, said precharge initiation device having a control input in electrical communication with said primary select node such that when said primary select signal has said first potential said precharge initiation device pulls said intermediate node toward said precharge potential. .Iaddend..Iadd.22. The circuit as specified in claim 21, wherein said output node is driven to said inactive potential by said primary select signal having said first potential. .Iaddend..Iadd.23. The circuit as specified in claim 21, further comprising:   a) a gate node in electrical communication with said intermediate node;   b) monitoring circuitry in electrical communication with said gate node, said monitoring circuitry generating a latch signal at said gate node in response to said inactive potential being on said output node; and   c) latch circuitry in electrical communication with said output node, said latch circuitry latching said inactive potential to said output node in   
     
     
        response to said latch signal. .Iaddend..Iadd.24.  A circuit for selecting an active or an inactive wordline responsive to a primary select signal and a secondary select signal, comprising: a) a primary select node for accepting said primary select signal;   b) a pass device electrically interposed between said wordline and said primary select node, actuation and deactuation of said pass device controllable by said secondary select signal;   c) a node electrically interposed intermediate said pass device and said wordline;   d) a precharge node connectable to a precharge potential; and   e) a precharge control device interposed between said precharge node and said intermediate node and in electrical communication with said primary select node, said precharge control device actuated in response to said primary select signal when said primary select signal has a value necessary to inactivate said wordline. .Iaddend..Iadd.25. A circuit for selecting a wordline, comprising:   decode circuitry for generating a primary select signal and a secondary select signal for selection and non-selection of said wordline in response to an address, each of said signals having an active state and an inactive state;   driver circuitry for taking said wordline to an active or an inactive potential in response to said primary and secondary select signals, said driver circuitry including a pass device activated by said secondary select signal having said active state;   a node electrically interposed intermediate said pass device and said wordline; and   a precharge circuit for charging the intermediate node to a desired potential, said precharge circuit actuated by said primary select signal when said primary select signal has a potential which takes said wordline   
     
     
        when non-selected to said inactive potential. .Iaddend..Iadd.26.  The circuit as specified in claim 25, wherein said wordline may be non-selected in response to said inactive state of said primary select signal. .Iaddend..Iadd.27. The circuit as specified in claim 25, further comprising a random access memory device including the circuit for selecting a wordline. .Iaddend..Iadd.28. The circuit as specified in claim 25 further comprising a computer including the circuit for selecting a wordline. .Iaddend..Iadd.29. A circuit adapted to precharge an intermediate node of a driver portion of a row decoder, said circuit comprising: an output capable of being driven to active and inactive potentials;   a primary select input for accepting a primary select signal of a first potential and a second potential for determining a potential of the output;   a pass device interposed between the intermediate node and the primary select input;   a precharge potential source; and   a precharge initiation device interposed between said precharge potential source and the intermediate node, said precharge initiation device controllable responsive to a primary select signal accepted by said primary select input such that when said primary select signal has said first potential said precharge initiation device pulls said intermediate node toward said precharge potential. .Iaddend..Iadd.30. The circuit as specified in claim 29, wherein said output is taken to said inactive potential by said primary select signal having said first potential.   
     
     
        .Iaddend..Iadd.31.  The circuit as specified in claim 29, further comprising: monitoring circuitry for generating a latch signal in response to said inactive potential being on said output node; and   latch circuitry for latching said inactive potential to said output node in response to said latch signal. .Iaddend..Iadd.32. A circuit for selecting an active or an inactive wordline responsive to a primary select signal and a secondary select signal, comprising:   a primary select input for accepting said primary select signal;   a pass device controlled by said secondary select signal interposed between said wordline and said primary select input;   a node interposed intermediate said pass device and said wordline;   a precharge potential source; and   a precharge control device interposed between said precharge potential source and said intermediate node and in communication with said primary select input, said precharge control device actuated in response to a primary select signal of a value necessary to inactivate said wordline. .Iaddend..Iadd.33. A circuit for selecting an active or an inactive wordline responsive to a primary select signal and a secondary select signal, comprising:   a primary select input for accepting said primary select signal;   a decode device controlled by said secondary select signal interposed between said wordline and said primary select input;   a node interposed intermediate said decode device and said wordline;   a precharge potential source; and   a precharge control device interposed between said precharge potential source and said intermediate node and in communication with said primary select input, said precharge control device actuated in response to a primary select signal of a value necessary to inactivate said wordline. .Iaddend..Iadd.34. A circuit for selecting an active or an inactive wordline responsive to a primary select signal and a secondary select signal, comprising:   a primary select input for accepting said primary select signal;   select circuitry controlled by said secondary select signal interposed between said wordline and said primary select input;   a node interposed intermediate said select circuitry and said wordline;   a precharge potential source; and   a precharge control device interposed between said precharge potential source and said intermediate node and in communication with said primary select input, said precharge control device actuated in response to a primary select signal of a value necessary to inactivate said wordline. .Iaddend.