Multiple level cell memory device with single bit per cell, re-mappable memory block
A system having a non-volatile memory device has a plurality of memory cells that are organized into memory blocks. Blocks can operate in either a multiple bit per cell mode or a single bit per cell mode. A processor controls the system and selects blocks to operate in the multiple bit per cell mode and single bit per cell mode. One dedicated memory block is capable of operating only in the single bit per cell mode. If the dedicated memory block is found to be defective, a defect-free block can be remapped to that dedicated memory block location to act only in the single bit per cell mode.
1. A system comprising:
a microcontroller coupled to and in communication with a memory device wherein the microcontroller generates control signals and communicates the control signals to the memory device through a control signal bus, generates address signals and communicates those address signals to the memory device through address input connections and reads and writes data from and to the memory device and wherein the data is communicated through input/output circuitry in the memory device;
the memory device further comprising:
a memory array comprising a plurality of memory cells arranged in rows and columns and organized into memory blocks including a first remappable memory block that operates only in a single bit storage configuration, the remaining memory blocks also remappable and adapted to operate in either the single bit storage configuration or a multiple bit storage configuration; and
configuration registers, for storing configuration bits indicating a storage configuration status of each of the memory blocks; and
control circuitry, coupled to an interface, the memory array and the configuration registers, for controlling which memory blocks store data in the multiple bit storage configuration and which memory blocks store data in the single bit storage configuration.
2. The system of claim 1 , further comprising a random access memory device, coupled to the data, address and control signals.
3. The device system of claim 2 wherein the random access memory device stores memory density configuration data read from the memory array during initialization.
4. The system of claim 1 wherein the first remappable memory block that operates only in the single bit storage configuration is block 0 of the device.
5. The system of claim 1 wherein the control circuitry executes single or multiple bit storage configuration read and write operations on the memory array in response to single and multiple bit read and write commands by the microcontroller.
6. The system of claim 1 further comprising random access memory in communication with the control signal bus, the address input connections and the input/output circuitry.
7. The system of claim 1 , the plurality of memory cell blocks comprising:
at least one error free memory cell block that is configured to operate only in the single bit storage configuration.
8. The system of claim 7 wherein the configuration register is comprised of one of a non-volatile programmable fuse apparatus, a volatile memory array, or both the non-volatile programmable fuse apparatus and the volatile memory array.
9. The system of claim 8 wherein the configuration register comprises at least one of trimming data, memory block lock data, record keeping data for the memory device, or data required for operation of the memory device.
10. The system of claim 9 wherein the memory device is a flash memory device wherein the memory array comprises a NAND architecture.