Write data mask method and system
View Patent ↗A method and system for performing byte-writes are described, where byte-writes involve writing only particular bytes of a multiple byte write operation. Embodiments include mask data that indicates which bytes are to be written in a byte-write operation. No dedicated mask pin(s) or dedicated mask line(s) are used. In one embodiment, the mask data is transmitted on data lines and store in response to a write_mask command. In one embodiment, the mask data is transmitted as part of the write command.
1. A method, comprising:
transmitting a data mask comprising a plurality of bits indicating corresponding bytes of multiple bytes of data to be written in a write operation from a first system component to a second system component as a portion of a write command over an address/command line of an interface coupling the first system component and the second system component;
transmitting the data from the first system component to the second system component over a data line of an interface coupling the first system component with the second system component, wherein the same data is transmitted over the data line in a plurality of consecutive bursts during a time period when the write command is a write mask command; and
writing particular bytes of the data from the data line into the second system component based on the write command.
2. The method of claim 1 , wherein the data mask is transmitted by the first component and stored in the second component to refer to a write to the second component.
3. The method of claim 1 , wherein the multiple bytes of data comprise thirty-two bytes of data, and wherein the data mask indicates which of the thirty-two bytes are to be written in response to the write command.
4. The method of claim 1 , wherein the data mask is stored in the second component in response to the write_mask command.
5. The method of claim 1 , wherein the write command is a write_with_mask command that directs only the indicated bytes to be written.
6. The method of claim 1 , wherein the write command is a write_nomask command that directs all of the multiple bytes to be written regardless of the data mask.
7. The method of claim 1 , wherein the write_mask command directs the data mask to be stored for reference during the write operation.
8. The method of claim 1 , further comprising:
determining whether the write operation is a byte-write operation, wherein only particular bytes of the multiple bytes are to be written in response to the write command;
on a condition that the write operation is a byte-write operation, executing a write_mask command; and
storing the data mask in response to the write_mask command.
9. The method of claim 8 , further comprising:
reading the stored data mask; and
writing the particular bytes indicated by the stored data mask.
10. The method of claim 1 , further comprising:
determining whether a write operation is a byte-write operation, wherein only particular bytes of the multiple bytes are to be written in response to the write command; and
on a condition that the write operation is a byte-write operation, transmitting the data mask to be read as a portion of the write command.
11. A system comprising:
a memory component;
an interface that includes a data line and an address/command line;
a processor coupled with the memory component through the interface and configured to:
transmit data to be written in the memory component over the data line;
transmit a write command over the address/command line wherein the write command comprises writing only particular bytes of multiple bytes of the data to be written during a write operation; and
transmit a data mask comprising a plurality of bits indicating corresponding bytes of multiple bytes of data to be written in response to the write command as a portion of the write command during a write operation, wherein the same data is transmitted over the data line in a plurality of consecutive bursts during a time period when the write command is a write_mask command.
12. The system of claim 11 , wherein the data mask is written to the memory component for reference in the write operation in response to the write_mask command.
13. The system of claim 11 , wherein the write command is a write_nomask command, in response to which all of the multiple bytes are written to the memory component regardless of the data mask.
14. The system of claim 11 , wherein the write command is a write_including_mask command that comprises a write command portion and a data mask portion.
15. A computer-readable medium having instructions stored thereon, that when executed causes a digital processing system to perform a method, the method comprising:
transmitting a data mask comprising a plurality of bits indicating corresponding bytes of multiple bytes of data to be written in a write operation from a first system component to a second system component as a portion of a write command over an address/command line of an interface coupling the first system component and the second system component;
transmitting the data from the first system component to the second system component over a data line of an interface coupling the first system component with the second system component, wherein the same data is transmitted over the data line in a plurality of consecutive bursts during a time period when the write command is a write mask command; and
writing particular bytes of the data from the data line into the second system component based on the write command.
16. The computer-readable medium of claim 15 , wherein the data mask is transmitted by the first component and stored in the second component to refer to a write to the second component.
17. The computer-readable medium of claim 15 , wherein the multiple bytes of data comprise thirty-two bytes of data, and wherein the data mask indicates which of the thirty-two bytes are to be written in response to the write command.
18. The computer-readable medium of claim 15 , wherein the data mask is stored in the second component in response to the write_mask command.
19. The computer-readable medium of claim 15 , wherein the write command is a write_with_mask command that directs only the indicated bytes to be written.
20. The computer-readable medium of claim 15 , wherein the write command is a write_nomask command that directs all of the multiple bytes to be written regardless of the data mask.
21. The computer-readable medium of claim 15 , wherein the write_mask command directs the data mask to be stored for reference during the write operation.
22. The computer-readable medium of claim 15 , wherein the method further comprises:
determining whether the write operation is a byte-write operation, wherein only particular bytes of the multiple bytes are to be written in response to the write command;
the write operation is a byte-write operation, executing a write_mask command; and
storing the data mask that is transmitted on the address/command line in response to the write_mask command.
23. The computer-readable medium of claim 22 , wherein the method further comprises:
reading the stored data mask; and
writing the particular bytes indicated by the stored data mask.
24. The computer-readable medium of claim 15 , wherein the method further comprises:
determining whether the write operation is a byte-write operation, wherein only particular bytes of the multiple bytes are to be written in response to the write command; and
the write operation is a byte-write operation transmitting the data mask to be read as a portion of the write command.