Semiconductor memory having both volatile and non-volatile functionality and method of operating
AssigneeZeno Semiconductor, Inc.
InventorYuniarto Widjaja
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Abstract
Semiconductor memory having both volatile and non-volatile modes and methods of operation. A semiconductor storage device includes a plurality of memory cells each having a floating body for storing, reading and writing data as volatile memory. The device includes a floating gate or trapping layer for storing data as non-volatile memory, the device operating as volatile memory when power is applied to the device, and the device storing data from the volatile memory as non-volatile memory when power to the device is interrupted.
Claims18
A method of operating a semiconductor storage device comprising a plurality of memory cells each having a floating body for storing, reading and writing data as volatile memory, a buried layer beneath said floating body, and a floating gate or trapping layer above said floating body for storing data as non-volatile memory, the method comprising:
- reading and storing data to the floating bodies as volatile memory while power is applied to the device;
- transferring the data stored in the floating bodies, by a parallel, non-algorithmic process, to the floating gates or trapping layers corresponding to the floating bodies, when power to the device is interrupted;
- and
- storing the data in the floating gates or trapping layers as non-volatile memory.
A method of selecting a semiconductor memory cell in a string, comprising a plurality of semiconductor memory cells each having a floating body for storing data as volatile memory, and a floating gate or trapping layer for storing data as non-volatile memory, the method comprising:
- selecting at least one of said semiconductor memory cells;
- and
- turning on at least one passing cell in said string, wherein each said passing cell is a cell not having been selected in said string.
A method of operating a semiconductor device to economize power usage, wherein said semiconductor device comprises a string of memory cells each having a floating body for storing, reading and writing data as volatile memory, and a floating gate or trapping layer for storing data as non-volatile memory, the method comprising:
- monitoring activity of at least one of said cells;
- and
- after a predetermined period of time during which said at least one cell has remained idle, performing a shadowing operation thereby storing a state of said at least one cell in said non-volatile memory.
Dependencies are inferred from the claim text.