Theory of Device Operation
(3) Flash digitizer circuit
This circuit is
(4) Viterbi detection circuit
The sample hold waveform output from the flash digitizer circuit is sent to the Viterbi detection circuit. The Viterbi detection circuit demodulates data according to the survivor path sequence.
(5) MEEPRM
This circuit converts the
4.6.4 Digital PLL circuit
The drive uses constant density recording to increase total capacity. This is different from the conventional method of recording data with a fixed data transfer rate at all data area. In the constant density recording method, data area is divided into zones by radius and the data transfer rate is set so that the recording density of the inner cylinder of each zone is nearly constant. The drive divides data area into 15 zones to set the data transfer rate.
The MPU transfers the data transfer rate setup data (SD/SC) to the RDC that includes the Digital PLL circuit to change the data transfer rate.
