Semiconductor memory device, and method of controlling the same

Abstract

A semiconductor device includes a memory core with a plurality of memory cells, an internal voltage generator and a low power entry circuit. The low power entry circuit receives a plurality of control signals which are provided to a command decoder, and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited. The internal voltage generator includes a detector and at least one of booster circuits. The internal voltage generator, coupled to the memory core via an internal power supply line, generates a boosted internal voltage based on an external voltage and supplies the boosted internal voltage to the memory core via the internal power supply line. The internal voltage generator stops supplying the boosted internal voltage to the internal power supply line in response to the low power signal while the external voltage is supplied to the semiconductor device.

1 - 6 . (canceled) 
     
     
         7 . A method of controlling a dynamic random access memory including dynamic memory cells, comprising:
 generating a first command to put the dynamic random access memory in a low power consumption mode, the first command including a first combination of a plurality of control signals, in which the dynamic memory cells in the dynamic random access memory do not retain data therein by stopping an operation of an internal voltage generator configured to supply an internal voltage to the dynamic memory cells in the low power consumption mode;
 keeping at least one signal of the plurality of control signals to a first voltage to maintain the low power consumption mode; and 
 turning the at least one signal of the plurality of control signals from the first voltage to a second voltage to put the dynamic random access memory out of the low power consumption mode, 
 wherein the dynamic random access memory continues to be supplied with a power supply voltage in the low power consumption mode. 
   
     
     
         8 . The method of controlling the dynamic random access memory according to  claim 7 , further comprising
 waiting for completion of initialization of the dynamic random access memory during a first period after the turning the at least one signal from the first voltage to the second voltage, the initialization being performed in response to the at least one signal being turned from the first voltage to the second voltage.   
     
     
         9 . The method of controlling the dynamic random access memory according to  claim 8 , wherein
 the internal voltage generated by the internal voltage generator in response to the turning to the second voltage is stabilized by the initialization.   
     
     
         10 . The method of controlling the dynamic random access memory according to  claim 8 , wherein
 the first period is equal to or more than 200 micro seconds.   
     
     
         11 . A method of controlling a dynamic random access memory including dynamic memory cells, comprising:
 generating a first command to put the dynamic random access memory in a low power consumption mode, the first command including a first combination of a plurality of control signals, in which the dynamic memory cells in the dynamic random access memory do not retain data therein by stopping a supply of an internal voltage in the low power consumption mode;   keeping at least one signal of the plurality of control signals to a first voltage to maintain the low power consumption mode; and   turning the at least one signal of the plurality of control signals from the first voltage to a second voltage to put the dynamic random access memory out of the low power consumption mode,   wherein the dynamic random access memory continues to be supplied with a power supply voltage in the low power consumption mode.   
     
     
         12 . The method of controlling the dynamic random access memory according to  claim 11 , further comprising
 waiting for completion of initialization of the dynamic random access memory during a first period after the turning the at least one signal from the first voltage to the second voltage, the initialization being performed in response to the at least one signal being turned from the first voltage to the second voltage.   
     
     
         13 . The method of controlling the dynamic random access memory according to  claim 12 , further comprising
 generating the internal voltage by an internal voltage generator in response to the turning to the second voltage, in which the internal voltage is stabilized by the initialization.   
     
     
         14 . The method of controlling the dynamic random access memory according to  claim 12 , wherein
 the first period is equal to or more than 200 micro seconds.   
     
     
         15 . A memory system comprising:
 a dynamic random access memory including dynamic memory cells;   a memory bus; and   a CPU coupled to the dynamic random access memory through the memory bus and configured to control the dynamic random access memory;   wherein the CPU
 generates a first command to put the dynamic random access memory in a low power consumption mode, the first command including a first combination of a plurality of control signals, in which the dynamic memory cells in the dynamic random access memory do not retain data therein by stopping a supply of an internal voltage in the low power consumption mode, 
 keeps at least one signal of the plurality of control signals to a first voltage to maintain the low power consumption mode; and 
 turning the at least one signal of the plurality of control signals from the first voltage to a second voltage to put the dynamic random access memory out of the low power consumption mode, and 
   wherein the dynamic random access memory continues to be supplied with a power supply voltage in the low power consumption mode.   
     
     
         16 . The memory system according to  claim 15 , wherein
 the CPU controls a non-volatile memory including flash memory cells through the memory bus.   
     
     
         17 . The memory system according to  claim 15 , wherein
 the CPU waits for completion of initialization of the dynamic random access memory during a first period after the turning the at least one signal of the plurality of control signals from the first voltage to the second voltage, the initialization being performed in response to the at least one signal being turned from the first voltage to the second voltage.   
     
     
         18 . The memory system according to  claim 17 , wherein
 the internal voltage supplied to the dynamic memory cells in response to the turning to the second voltage is stabilized by the initialization.   
     
     
         19 . The memory system according to  claim 17 , wherein
 the first period is equal to or more than 200 micro seconds.