System and method to reduce read latency of a data storage device

1. A method comprising:

in a data storage device that includes a memory and a controller performing:

receiving a read request that indicates a logical address, the read request received from a host device while the data storage device is operatively coupled to, or embedded within, the host device;

performing a first read operation to retrieve, from the memory, a representation of an entry of a logical mapping table that corresponds to the logical address;

performing a second read operation to retrieve a representation of a codeword from the memory, wherein the representation of the codeword includes the representation of the entry;

decoding the representation of the codeword to determine whether an error exists at the entry; and

prior to completion of decoding, initiating a third read operation to retrieve first read data from a first physical address corresponding to the logical address as determined based on the representation of the entry.

2. The method of claim 1 , further comprising, after retrieving the first read data, decoding the first read data to produce error corrected data and transferring the error corrected data to the host device.

3. The method of claim 1 , further comprising, when decoding the representation of the codeword identifies an error at the entry, initiating a fourth read operation to retrieve second read data from a second physical address corresponding to the logical address as determined based on a corrected representation of the codeword.

4. The method of claim 3 , wherein the third read operation is discontinued when the fourth read operation is initiated.

5. The method of claim 3 , wherein results of the third read operation are discarded if the fourth read operation is initiated.

6. The method of claim 3 , further comprising, after retrieving the second read data, decoding the second read data to produce error corrected data and transferring the error corrected data to the host device.

7. The method of claim 1 , further comprising determining whether a portion of the logical mapping table that is in the controller includes the logical address.

8. The method of claim 1 , further comprising, after retrieving the representation of the entry, checking error detection data associated with the entry, wherein the third read operation is initiated when the error detection data does not indicate an error in the representation of the entry.

9. The method of claim 8 , wherein the error detection data includes a parity bit associated with the entry, and wherein the representation of the codeword is decoded based on error detection and correction data associated with the codeword.

10. The method of claim 1 , further comprising, after retrieving the representation of the entry, descrambling the representation of the entry before initiating the third read operation.

11. A data storage device comprising:

a memory; and

a controller coupled to the memory, wherein the controller includes a first logical mapping table and is configured to:

receive a read request that indicates a logical address, the read request received from a host device while the data storage device is operatively coupled to, or embedded within, the host device;

perform a first read operation to retrieve, from the memory, a representation of an entry of a logical mapping table that corresponds to the logical address;

perform a second read operation to retrieve a representation of a codeword from the memory, the representation of the codeword including the representation of the entry;

decode the representation of the codeword to determine whether an error exists at the entry; and

prior to completion of decoding, initiate a third read operation to retrieve first read data from a first physical address corresponding to the logical address as determined based on the representation of the entry.

12. The data storage device of claim 11 , wherein the controller is configured to, after retrieving the first read data, decode the first read data to produce error corrected data and transfer the error corrected data to the host device.

13. The data storage device of claim 11 , wherein the controller is configured to, when decoding the representation of the codeword identifies an error at the entry, initiate a fourth read operation to receive second read data from a second physical address corresponding to the logical address as determined based on a corrected representation of the codeword.

14. The data storage device of claim 13 , wherein the controller is configured to discontinue the third read operation when the fourth read operation is initiated.

15. The data storage device of claim 13 , wherein the controller is configured to discard results of the third read operation if the fourth read operation is initiated.

16. The data storage device of claim 13 , wherein the controller is configured to, after retrieving the second read data, decode the second read data to produce error corrected data and transfer the error corrected data to the host device.

17. The data storage device of claim 11 , wherein the controller is configured to determine whether a portion of the logical mapping table that is in the controller includes the logical address.

18. The data storage device of claim 11 , wherein the controller is configured to, after retrieving the entry, check error detection data associated with the entry, wherein the third read operation is initiated when the error detection data does not indicate an error in the representation of the entry.

19. The data storage device of claim 18 , wherein the error detection data includes a parity bit associated with the entry, and wherein the representation of the codeword is decoded based on error detection and correction data associated with the codeword.

20. The data storage device of claim 11 , wherein the controller is configured to, after retrieving the representation of the entry, descramble the representation of the entry before initiating the third read operation.