A CD-ROM Data Retreiver IC

The functional structure of a programmable CD-ROM data retreiver IC is discussed here. The chip operates on serial streams of CD data from an already available EFM demodulator/decoder chip, designated here as CD2A, and performs a number of data manipulations such as; descrambling, reformatting and CRC error checks, etc. The chip can be programmed to locate and transfer desired data blocks and/or bytes to a host processor through an I/O bus interface. Slow serial data transfers, e.g. RS232, can also be performed, if needed by utilising the appropriate facilities of the system's microcontroller.