Accumulating read channel performance data

A system, comprising:

• at least one magnetic storage disk having a plurality of formatted data sectors;
• at least one transducer configured to extract an encoded data signal from the magnetic storage disk;
• a read channel configured to extract encoded data symbols from the encoded data signal;
• and
• a programmable channel quality monitor to accumulate performance data samples corresponding to a recorded test data sequence spanning two or more data sectors of the magnetic medium, wherein the channel quality monitor includes an accumulator to accumulate the performance data samples and a measurement counter to count the number of performance data samples accumulated in the accumulator, wherein the channel quality monitor receives a sector span signal and a signal indicating an end of a sector, and the channel quality monitor is configured such that, while the sector span signal is active, the signal indicating the end of a sector is prevented from triggering a reset of the measurement counter and the accumulator calculates a first performance measure from performance data from at least two data sectors.

A method of accumulating performance data in a programmable channel quality monitor from a read channel configured to extract data symbols from a magnetic medium having a plurality of formatted data sectors, the method comprising:

• activating a sector span signal of the channel quality monitor that includes an accumulator to accumulate performance data samples and a measurement counter to count the number of performance data samples accumulated in the accumulator;
• in the channel quality monitor, receiving a signal indicating an end of a sector;
• while the sector span signal is active, preventing the signal indicating the end of a sector from triggering a reset of the measurement counter;
• and
• while the sector span signal is active, accumulating performance data samples corresponding to a recorded test data sequence spanning two or more data sectors of the magnetic medium in the accumulator, wherein accumulating performance data samples comprises calculating a first performance measure from performance data from at least two data sectors.

A method of accumulating performance data from a read channel configured to extract data symbols from a magnetic medium having a plurality of formatted data sectors, comprising:

• writing an original test data pattern to multiple data sectors of the magnetic medium;
• reading the original test pattern from the multiple data sectors of the magnetic medium to produce a readback test pattern;
• activating a sector span signal of a channel quality monitor that includes an accumulator to accumulate performance data samples and a measurement counter to count the number of performance data samples accumulated in the accumulator;
• in the channel quality monitor, receiving a signal indicating an end of a sector;
• while the sector span signal is active, preventing the signal indicating the end of a sector from triggering a reset of the measurement counter;
• and
• in the accumulator of the programmable channel quality monitor, accumulating performance data samples relating to a comparison of the original test pattern and the readback test pattern, wherein accumulating performance data comprises calculating a first performance measure from performance data from at least two data sectors while the sector span signal is active.

A method for monitoring a read channel with a channel quality monitor, the read channel being configured to extract data from a magnetic medium storing test data in a plurality of data sectors, the method comprising:

• activating a sector span signal of the channel quality monitor that includes an accumulator to accumulate performance data samples and a measurement counter to count the number of performance data samples accumulated in the accumulator;
• in the channel quality monitor, receiving a signal indicating an end of a sector;
• while the sector span signal active, preventing the signal indicating the end of a sector from triggering a reset of the measurement counter;
• and
• while the sector span signal is active, accumulating performance data from at least two data sectors of the plurality of data sectors in the accumulator of the channel quality monitor.