Combined soft detection/soft decoding in tape drive storage channels

A tape drive system, comprising:

• a soft detector, comprising:
• logic, implemented in a first hardware engine, adapted for executing a first forward loop of a detection algorithm on a first block of signal samples during a first time interval;
• logic, implemented in a second hardware engine, adapted for executing a first reverse loop of the detection algorithm on the first block of signal samples during the first time interval to produce first soft information;
• logic, implemented in a third hardware engine, adapted for executing a second forward loop of the detection algorithm on the first block during a third time interval;
• and
• logic, implemented in a fourth hardware engine, adapted for executing a second reverse loop of the detection algorithm on the first block during the third time interval to produce third soft information;
• a soft decoder, comprising logic, implemented in a fifth hardware engine, adapted for executing a decoding algorithm on the first block during a second time interval using the first soft information to produce the second soft information and for executing the decoding algorithm on the first block during a fourth time interval using the third soft information;
• and
• logic adapted for outputting a first decoded block of signal samples based on the executing the decoding algorithm on the first block during the fourth time interval using the third soft information,
• wherein a sum of the second, third, and fourth time intervals are about equal in duration to the first time interval.

A tape drive system, comprising:

• a soft detector, comprising:
• logic, implemented in a first hardware engine, adapted for executing a first forward loop of a detection algorithm on a first block of signal samples during a first time interval;
• logic, implemented in a second hardware engine, adapted for executing a first reverse loop of the detection algorithm on the first block during a second time interval;
• logic, implemented in a fourth hardware engine, adapted for executing a second forward loop of the detection algorithm on the first block during a fourth time interval using second soft information;
• and
• logic, implemented in a fifth hardware engine, adapted for executing a second reverse loop of the detection algorithm on the first block during a fifth time interval using the second soft information,
• wherein the soft detector passes first soft information to a soft decoder based on the executing of the first forward and reverse loops of the detection algorithm on the first block, and
• wherein the soft detector passes third soft information to the soft decoder based on the executing of the second forward and reverse loops of the detection algorithm on the first block;
• the soft decoder, comprising:
• logic, implemented in a third hardware engine, adapted for executing a decoding algorithm on the first block during a third time interval using the first soft information and for executing the decoding algorithm on the first block during a sixth time interval using the third soft information, wherein the soft decoder produces the second soft information based on the executing of the decoding algorithm on the first block during the third time interval;
• and
• logic adapted for outputting a first decoded block of signal samples based on the executing the decoding algorithm on the first block during the sixth time interval,
• wherein a sum of the second, third, fourth, fifth, and sixth time intervals are about equal in duration to twice the first time interval.

A tape drive system, comprising:

• a soft detector, comprising:
• logic, implemented in a first hardware engine, adapted for executing a first forward loop of a detection algorithm on a first block of signal samples during a first time interval;
• logic, implemented in a second hardware engine, adapted for executing a first reverse loop of the detection algorithm on the first block during the first time interval;
• logic, implemented in a fourth hardware engine, adapted for executing a second forward loop of the detection algorithm on the first block during a third time interval using second soft information;
• and
• logic, implemented in a fifth hardware engine, adapted for executing a second reverse loop of the detection algorithm on the first block during the third time interval using the second soft information,
• wherein the soft detector passes first soft information to a soft decoder based on the executing of the first forward and reverse loops of the detection algorithm on the first block, and
• wherein the soft detector passes third soft information to the soft decoder based on the executing of the second forward and reverse loops of the detection algorithm on the first block;
• the soft decoder, comprising:
• logic, implemented in a third hardware engine, adapted for executing a decoding algorithm on the first block during a second time interval using the first soft information and for executing the decoding algorithm on the first block during a fourth time interval using the third soft information, wherein the soft decoder produces the second soft information based on the executing of the decoding algorithm on the first block during the second time interval;
• and
• logic adapted for outputting a first decoded block of signal samples based on the executing the decoding algorithm on the first block during the fourth time interval,
• wherein a sum of the second, third, and fourth time intervals are about equal in duration to twice the first time interval.