Stopping rules for turbo product codes

1. A system, comprising:

a row decoder configured to perform row decoding on a plurality of row codewords in an array in order to produce a row-decoded array that includes a plurality of row-decoded column codewords;

a column decoder configured to perform column decoding on the plurality of row-decoded column codewords in order to produce a row-decoded and column-decoded array that includes: (1) a plurality of row-decoded and column-decoded row codewords and (2) a plurality of row-decoded and column-decoded column codewords; and

a turbo product code (TPC) decoding controller configured to:

determine a number of row-decoded and column-decoded row codewords that are not in a row codebook;

determine a number of row-decoded and column-decoded column codewords that are not in a column codebook; and

output at least a data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0 and (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1.

2. The system of claim 1 , wherein the system includes a semiconductor device, including one or more of the following: an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

3. The system of claim 1 , wherein the TPC decoding controller is further configured to output at least the data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0 and (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 0.

4. The system of claim 3 , wherein:

the system further includes a multiplexer that is configured to select between (1) read data from storage and (2) the row-decoded and column-decoded array output by the column decoder, wherein the row decoder inputs output of the multiplexer; and

the TPC decoding controller is further configured to:

determine if a maximum number of decoding attempts has been reached;

in the event it is determined that the maximum number of decoding attempts has been reached, declare a decoding failure; and

in the event it is determined that the maximum number of decoding attempts has not been reached, configure the multiplexer to select the row-decoded and column-decoded array output by the column decoder, wherein the row decoder performs row decoding on the plurality of row codewords in the row-decoded and column-decoded array.

5. The system of claim 1 , wherein a number of columns combined to generate a column codeword is less than a threshold.

6. The system of claim 1 , wherein the TPC decoding controller is further configured to:

perform error checking on a data portion of the row-decoded and column-decoded array;

output at least the data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0, (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1, and (3) the data portion passes the error check; and

not output the data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0, (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1, and (3) the data portion does not pass the error check.

7. The system of claim 6 , wherein a number of columns combined to generate a column codeword is greater than or equal to a threshold.

8. The system of claim 6 , wherein:

the plurality of row codewords include cyclic redundancy check (CRC) bits such that the row decoder is configured to perform row decoding on the CRC bits; and

the plurality of column codewords include the CRC bits such that the column decoder is configured to perform column decoding on the CRC bits.

9. A method, comprising:

performing row decoding on a plurality of row codewords in an array in order to produce a row-decoded array that includes a plurality of row-decoded column codewords;

performing column decoding on the plurality of row-decoded column codewords in order to produce a row-decoded and column-decoded array that includes: (1) a plurality of row-decoded and column-decoded row codewords and (2) a plurality of row-decoded and column-decoded column codewords;

determining a number of row-decoded and column-decoded row codewords that are not in a row codebook;

determining a number of row-decoded and column-decoded column codewords that are not in a column codebook; and

outputting at least a data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0 and (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1.

10. The method of claim 9 , wherein the method is performed by a semiconductor device, including one or more of the following: an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

11. The method of claim 9 , wherein the TPC decoding controller is further configured to output at least the data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0 and (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 0.

12. The method of claim 11 , further comprising:

selecting between (1) read data from storage and (2) the row-decoded and column-decoded array output by the column decoder, wherein the row decoder inputs output of the multiplexer;

determining if a maximum number of decoding attempts has been reached;

in the event it is determined that the maximum number of decoding attempts has been reached, declaring a decoding failure; and

in the event it is determined that the maximum number of decoding attempts has not been reached, configuring the multiplexer to select the row-decoded and column-decoded array output by the column decoder, wherein the row decoder performs row decoding on the plurality of row codewords in the row-decoded and column-decoded array.

13. The method of claim 9 , wherein a number of columns combined to generate a column codeword is less than a threshold.

14. The method of claim 9 , wherein the TPC decoding controller is further configured to:

performing error checking on a data portion of the row-decoded and column-decoded array;

outputting at least the data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0, (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1, and (3) the data portion passes the error check; and

not outputting the data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0, (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1, and (3) the data portion does not pass the error check.

15. The method of claim 14 , wherein a number of columns combined to generate a column codeword is greater than or equal to a threshold.

16. The method of claim 14 , wherein:

the plurality of row codewords include cyclic redundancy check (CRC) bits such that the row decoder is configured to perform row decoding on the CRC bits; and

the plurality of column codewords include the CRC bits such that the column decoder is configured to perform column decoding on the CRC bits.

17. A computer program product, the computer program product being embodied in a non-transitory computer readable storage medium and comprising computer instructions for:

performing row decoding on a plurality of row codewords in an array in order to produce a row-decoded array that includes a plurality of row-decoded column codewords;

performing column decoding on the plurality of row-decoded column codewords in order to produce a row-decoded and column-decoded array that includes: (1) a plurality of row-decoded and column-decoded row codewords and (2) a plurality of row-decoded and column-decoded column codewords;

determining a number of row-decoded and column-decoded row codewords that are not in a row codebook;

determining a number of row-decoded and column-decoded column codewords that are not in a column codebook; and

outputting at least a data portion of the row-decoded and column-decoded array in the event: (1) the number of row-decoded and column-decoded row codewords not in the row codebook equals 0 and (2) the number of row-decoded and column-decoded column codewords not in the column codebook equals 1.