Read mode for flash memory
View Patent ↗A method for reading a nonvolatile memory array including an array of memory cells, each memory cell including a substrate, a control gate, a charge storage element, a source region and a drain region, includes receiving, at an address register, a read command including an address for a memory cell in the array of memory cells and an indication regarding whether the read command is a full page read command or a partial page read command. A starting address for a page including the received address is identified, wherein the page includes multiple rows of memory cells in the array of memory cells. The address register is reset to the starting address for the page. It is determined whether all memory cells in the page are non-programmed. Data indicative of a non-programmed state of the page is output if it is determined that all memory cells in the page are non-programmed.
1. A device comprising:
an array of memory cells; and
one or more components to:
receive a read command including an address for a memory cell, of the array of memory cells, and an indication regarding whether the read command is a full page read command or a partial page read command,
identify a page associated with the received address, the page including multiple rows of memory cells, of the array of memory cells,
determine whether the received read command indicates that the received read command is a partial page read command when all memory cells in a selected row in the page are in a non-programmed state, and
output data indicative of the non-programmed state of the selected row when the read command is a partial page read command.
2. The device of claim 1 , where, when identifying the page including the received address, the one or more components are to:
identify a starting address for the page, and
set an address register, associated with the device, to the starting address.
3. The device of claim 1 , where the one or more components are further to:
read a dynamic reference bit associated with the selected row, and
determine whether all memory cells in the selected row are in a non-programmed state based on the dynamic reference bit.
4. The device of claim 1 , where the one or more components are further to:
determine whether all rows associated with the page are read when the read command is not a partial page read command; and
output data, indicative of data stored in at least one of the rows associated with the page, to an output memory when all rows associated with the page are read.
5. The device of claim 4 , where the one or more components are further to:
increment a row address to a starting address for a next row when all rows associated with the page are not read, and
read data in the next row upon incrementing the row address.
6. The device of claim 1 , where the one or more components are further to:
read a reference bit associated with the selected row, and
determine that one or more memory cells, associated with the selected row, have been programmed based on the reference bit.
7. The device of claim 1 , where the one or more components are further to:
read a memory cell in the selected row, and
determine, after reading the memory cell, whether each column associated with the selected row has been read.
8. The device of claim 7 , where the one or more components are further to:
increment a column address to a next column in the selected row when each column, associated with the selected row, has not been read, and
read the next column.
9. The device of claim 8 , where the one or more components are further to:
determine that each column associated with the selected row has been read, and identify a page mode associated with the read command when each column associated with the selected row has been read.
10. A memory device comprising:
an array of non-volatile memory cells, the array comprising:
a plurality of columns, and
a plurality of rows;
control logic to receive a read command identifying a memory cell to be read, where the read command includes a row address designating a selected row, of the plurality of rows, and a column address designating a selected column, of the plurality of columns;
control logic to determine whether each memory cell, in the selected row, is in a non-programmed state;
control logic to determine whether the received read command indicates that the received read command is a partial page read command when each memory cell, in the selected row, is in the non-programmed state; and
control logic to output data to an output memory indicative of the non-programmed state of the memory cells in the selected row.
11. The memory device of claim 10 , further comprising:
control logic to identify a starting address, including a first column address, for the selected row based on the received read command; and
control logic to set an address register, associated with the memory device, to the first column address.
12. The memory device of claim 10 , comprising:
control logic to perform read operations on all memory cells in the selected row when at least one memory cell in the selected row is not in a non-programmed state; and
control logic to output data to an output memory indicative of data stored in the selected row when the received read command includes a partial page read command.
13. The memory device of claim 12 , where the selected row is associated with a page,
the memory device further comprising:
control logic to determine whether all rows in the page have been read when the received read command includes a full page read command;
control logic to increment the row address to a next row in the page when all rows in the page have not been read; and
control logic to read the next row in the page.
14. The memory device of claim 13 , where, when incrementing the row address to the next row in the page, the control logic is to increment the row address to a starting address for the next row.
15. The memory device of claim 12 , further comprising:
control logic to determine whether all columns in the selected row have been read when the at least one memory cell in the selected row is not in a non-programmed state;
control logic to increment the column address to a next column in the selected row when all columns in the selected row have not been read; and
control logic to read the next column in the selected row upon incrementing the column address.
16. The memory device of claim 10 , where the control logic to determine whether each memory cell in the selected row is in the non-programmed state comprises:
control logic to read a dynamic reference bit associated with the selected row,
where the control logic determines, based on the dynamic reference bit, whether each memory cell, in the selected row, is in the non-programmed state.
17. The memory device of claim 10 , further comprising:
a plurality of sense amplifiers operatively connected to a plurality of bit lines, associated with the plurality of columns, for sensing a threshold voltage for memory cells connected to the bit lines.
18. The memory device of claim 10 , further comprising:
control logic to configure a dynamic reference bit associated with a selected row of memory cells in the page to indicate whether all memory cells in the selected row are in a non-programmed state.
19. The memory device of claim 10 , where at least one of the memory cells includes a semiconductor-oxide-nitride-semiconductor (SONOS) type NOR memory cell.