Adaptive programming for flash memories

Abstract

A method to adjust the programming voltage in flash memory when the programming time exceeds specification. A method to adjust the programming voltage of flash memory after a predetermined number of erase/write cycles.

1 . A method for programming a flash memory comprising:
 determining a time to program a portion of said flash memory at a programming voltage;   determining an adaptive programming voltage based upon said time to program said portion of said flash memory at said programming voltage; and   using said adaptive programming voltage for future programming of said portion of said flash memory.   
     
     
         2 . The method of  claim 1  wherein said programming is an erase operation. 
     
     
         3 . The method of  claim 1  wherein said programming is a write operation. 
     
     
         4 . The method of  claim 1  where in said programming is an erase operation plus a write operation. 
     
     
         5 . The method of  claim 1  wherein said adaptive programming voltage is a control gate voltage. 
     
     
         6 . The method of  claim 1  wherein said adaptive programming voltage is a well voltage. 
     
     
         7 . The method of  claim 1  wherein said portion of said flash memory is a memory block, a memory sector, or all bits in said flash memory. 
     
     
         8 . The method of  claim 1  where said adaptive programming voltage is a control gate voltage plus a well voltage. 
     
     
         9 . A method of programming a flash circuit, comprising:
 indexing a counter after each erase/write cycle is performed on a portion of a flash memory in said flash circuit;   checking a programming time after said counter reaches a predetermined number of erase/write cycles;   when said counter reaches said predetermined number of erase/write cycles and said programming time exceeds a programming time specification, selecting a new adaptive programming voltage, then writing said new adaptive programming voltage into said flash memory, and using said new adaptive programming voltage for future programming of said portion of said flash memory; and   resetting said counter after reaching said predetermined number of erase/write cycles.   
     
     
         10 . The method of  claim 9  wherein said programming is to erase said flash memory in said flash circuit. 
     
     
         11 . The method of  claim 9  wherein said programming is to write to said flash memory in said flash circuit. 
     
     
         12 . The method of  claim 9  wherein said programming is an erase plus a write to said flash memory in said flash circuit. 
     
     
         13 . The method of  claim 9  wherein said adaptive programming voltage is a control gate voltage. 
     
     
         14 . The method of  claim 9  wherein said adaptive programming voltage is a well voltage. 
     
     
         15 . The method of  claim 9  wherein said portion of said flash memory is a memory block, a memory sector, or all bits in said flash memory. 
     
     
         16 . The method of  claim 9  where said adaptive programming voltage is a control gate voltage plus a well voltage.