Eight-to-fourteen modulation. This low-level and very critical channel coding technique maximizes pit sizes on the disc by reducing frequent transitions from 0 to 1 or 1 to 0. CD represents 1's as Land-pit transitions along the track. The 8/14 code maps 8 user data bits into 14 channel bits in order to avoid single 1's and 0's, which would otherwise require replication to reproduce extremely small artifacts on the disc. In the 1982 compact disc standard (IEC 908 standard), 3 merge bits are added to the 14 bit block to further eliminate 1-0 or 0-1 transitions between adjacent 8/14 blocks.
Eight to Fourteen Modulation: used on every CD for modulation and error correction.
Eight to Fourteen Modulation. An encoding technique used to convert 8 bits of digital data to 14 bits. The CD player performs EFM demodulation.
Eight to Fourteen Modulation is used during encoding, because the 8-bit 'magnetic' Byte has to be modulated to a 14-bit 'optical' Byte. During the read process, the interface demodulates the 14- bit optical code to the 8-bit code used by the computer--and all modulation and processing remains transparent to the user. EIDE - An acronym for Extended Imbedded Drive Electronics. Also known as ATA (AT Attachment -From the days of the IBM AT) or ATAPI (AT Attachment Packet Interface), this is the standard interface in most computers. The first computers had proprietary controllers for hard disk control, and experienced interchangeability problems. The electronics are now imbedded on the peripheral for compatibility, and connect to a host adapter chip on the motherboard. Data transfer rates have reached 100 MB/sec with the introduction of the ATA-100 standard. Some limitations of the EIDE bus are cable length (maximum 18 inches) and the number of devices supported (maximum of two on each cable). A maximum of two buses (four devices) are supported.
A low-level and critical channel coding technique that maximizes pit sizes on the disc by reducing frequent transitions from 0 to 1 or 1 to 0. For example, CD employs pulse width modulation (PCM), representing 1s as land-pit transitions along the track. The 8/14 code maps 8 user data bits into 14 channel bits. In the 1982 CD standard (IEC 908), 3 merge bits are added to the 14-bit block to further eliminate 1-to-0 or 0-to-1 transitions between adjacent 8/14 blocks.
DVD's EFM+ method is a derivative of EFM. It folds the merge bits into the main 8/16 table.
Eight bit to Fourteen bit Modulation code more...