DSP-based clock recovery for a digital magnetic data channel

A DSP-based clock recovery system for a digital magnetic recording channel is presented which utilises an infinite impulse response (IIR) filter. The performance has been evaluated using software simulation, verified in real-time operation on a Texas Instruments TMS320C25 processor. Data coded in Manchester, Miller, Miller and 2,7 codes have been applied. In each case synchronization is achieved within the first symbol period even in the presence of jitter. The system can withstand data dropouts of 40 bit periods without losing synchronization. This can be increased when filter sections are cascaded.