Command-based control of NAND flash memory
View Patent ↗Some embodiments of the invention use a command-based interface to control reads and writes with non-volatile memory devices. This may reduce the number of pins that are needed on each integrated circuit, and therefore reduce the cost and size of those integrated circuits. In some embodiments, an on-die cache buffer may be used to buffer data transfers between a high-speed memory bus and the slower speed non-volatile array.
1. A method, comprising:
receiving a command for operation of a non-volatile memory device on a set of input/output lines, the command indicating a read operation or a write operation;
receiving an address on the set of input/output lines subsequent to receiving the command, the address indicating a starting location of a data transfer operation; and
receiving data on the set of input/output lines subsequent to receiving the address, the data to be transferred to or from a block of addresses in the non-volatile memory device starting with the received address;
wherein:
a single clock signal is used to latch the address and data;
said receiving the command comprises interpreting signals on the input/output lines as a command for a first number of clock cycles;
said receiving the address comprises interpreting signals on the input/output lines as an address for a second number of clock cycles; and
said receiving the data comprises interpreting signals on the input/output lines as data for a third number of clock cycles;
the third number of clock cycles is indicated in the command.
2. The method of claim 1 , wherein another signal is used to latch the command.
3. The method of claim 1 , wherein said receiving a command comprises receiving a command for operation of a NAND flash memory device.
4. The method of claim 1 , further comprising automatically returning to a receive mode of operation subsequent to said receiving the data.