Constant-Density Writing for Magnetic Storage Media

An apparatus comprising:

• an interface to receive write data from a host;
• a disk of magnetic storage media to store the write data, the disk including multiple concentric tracks;
• a magnetic media writer configured to write the write data to the magnetic storage media as data bits;
• and
• a constant-density writer configured to:
• determine respective bit periods for ones of the multiple concentric tracks, each bit period of the respective bit periods associated with a particular concentric track of the multiple concentric tracks, the respective bit periods varying based on respective radiuses of the multiple concentric tracks;
• the respective bit periods being configured to maintain a particular bit density across the multiple concentric tracks;
• select, for the write data, a concentric track from among the multiple concentric tracks, the concentric track being associated with a bit period of the respective bit periods;
• delay, based on the bit period of the concentric track, transitions between bits of the write data to generate phase-delayed write data, the delaying effective to cause bits of the phase-delayed write data to have the bit period associated with the concentric track;
• and
• transmit, to the magnetic media writer, the phase-delayed write data to enable the concentric track to have the particular bit density.

A System-on-Chip (SoC) comprising:

• an interface to a host from which write data is received for writing to magnetic storage media;
• an interface to a media writer of the magnetic storage media;
• and
• a constant-density writer implemented at least partially in hardware, the constant-density writer configured to:
• determine respective bit periods for ones of the multiple concentric tracks, each bit period of the respective bit periods associated with a particular concentric track of the multiple concentric tracks, the respective bit periods varying based on respective radiuses of the multiple concentric tracks;
• the respective bit periods being configured to maintain a particular bit density across the multiple concentric tracks;
• select, for the write data, a concentric track from among the multiple concentric tracks, the concentric track being associated with a bit period of the respective bit periods;
• delay, based on the bit period of the concentric track, transitions between bits of the write data to generate phase-delayed write data, the delaying of the transitions being effective to cause bits of the phase-delayed write data to have the bit period associated with the concentric track;
• and
• transmit, to the magnetic media writer, the phase-delayed write data to enable the concentric track to have the particular bit density.