Granted Patent B1

US 8,886,874 · App. 13/925,807 · Granted Nov 11, 2014

Abstract

Claims (25)

1. A method for operating a flash memory performed by a memory controller, wherein the memory controller is in communication with a processor, and the flash memory includes a plurality of sectors, each sector including a plurality of memory cells, the method comprising:

populating an internal table in the memory controller with a plurality of attributes corresponding to the plurality of sectors, wherein the plurality of attributes includes at least one of a sector size, sector count, sector address range, and memory cell address range;

receiving a first memory read access command from the processor that includes a plurality of address bits corresponding to a memory cell address of a memory cell that is currently being accessed, wherein the plurality of address bits includes a first set of sector address bits corresponding to a current sector address of a current sector associated with the memory cell, and a first set of memory cell address bits corresponding to a sector specific memory cell address of the memory cell;

comparing the current sector address with a previous sector address stored in the memory controller and the flash memory, wherein the previous sector address corresponds to a previous sector accessed during execution of a previous memory read access command;

transmitting the first set of memory cell address bits to the flash memory during an address cycle of the first memory read access command when the previous sector address and the current sector address are identical;

replacing the previous sector address stored in the memory controller and the flash memory with the current sector address when the previous sector address and the current sector address are different;

transmitting the plurality of address bits to the flash memory during the address cycle of the first memory read access command when the previous sector address and the current sector address are different;

receiving at least one of the first set of memory cell address bits and the plurality of address bits by the flash memory;

appending the current sector address to the sector specific memory cell address by the flash memory to generate the memory cell address; and

accessing the memory cell using the memory cell address.

2. The method of claim 1 , further comprising marking at least one of the one or more sectors as a default sector for an initial memory read access command received by the memory controller.

3. The method of claim 2 , further comprising storing a default sector address corresponding to the default sector in both the memory controller and the flash memory.

4. The method of claim 1 , wherein the first memory read access command further includes a plurality of instruction bits, a plurality of dummy data bits, and a plurality of data bits.

5. The method of claim 1 , wherein the flash memory is a serial NOR flash memory.

6. A memory controller for operating a flash memory, wherein the memory controller is in communication with a processor, wherein the flash memory includes one or more sectors, each sector including a plurality of memory cells, the memory controller comprising:

an internal table generator for populating and storing an internal table with one or more attributes corresponding to the one or more sectors, wherein the one or more attributes includes at least one of a sector size, sector address, and memory cell address range, wherein the internal table is stored in the memory controller;

a memory read access command receiver for receiving a first memory read access command from the processor, wherein the first memory read access command includes a plurality of address bits corresponding to a memory cell address of a memory cell that is currently accessed to execute the first memory read access command, wherein the plurality of address bits includes a first set of sector address bits corresponding to a current sector address of a current sector associated with the memory cell and a first set of memory cell address bits corresponding to a sector specific memory cell address of the memory cell;

a sector address comparator for comparing the current sector address with a previous sector address stored in both the memory controller and the flash memory corresponding to a previous sector accessed during execution of a previous memory read access command and replacing the previous sector address stored in the memory controller and the flash memory with the current sector address when the previous sector address and the current sector address are different, wherein the sector address comparator accesses the internal table to read the current sector address for transmitting to the flash memory; and

an address transmitter for transmitting at least one of the plurality of address bits and the first set of memory cell address bits to the flash memory during an address cycle of the first memory read access command based on the comparison of the previous sector address with the current sector address,

wherein the flash memory appends the current sector address to the sector specific memory cell address to generate the memory cell address when the previous sector address and the current sector address are identical,

and wherein the flash memory accesses the memory cell using the memory cell address.

7. The memory controller of claim 6 , wherein the sector address comparator marks at least one of the one or more sectors as a default sector for an initial memory read access command received by the memory controller.

8. The memory controller of claim 7 , wherein the sector address comparator stores a default sector address corresponding to the default sector in the memory controller and the flash memory.

9. The memory controller of claim 6 , wherein the first memory read access command further includes a plurality of instruction bits, a plurality of dummy data bits, and a plurality of data bits.

10. The memory controller of claim 6 , wherein the flash memory is a serial NOR flash memory.

Assignments (22)