| 摘要 |
A one stage CRC generation system (400) and a two stage CRC generation system (600) feature a CRC generator/checker (700) which outputs a programmable number of CRC bytes. The CRC generation/checker (700) comprises a segmenting circuit (710) [for segmenting an input stream of user data into a plurality m of sub-streams]; a circuit (712) which forms a linear combination of the plurality m of sub-streams and operates upon the linear combination in order to generate CRC bytes; and, a checker circuit (714) for comparing the generated CRC bytes with previously generated CRC bytes. The two stage system (600) includes a first CRC generator/checker (601); a memory (602) which receives both the user data and K1 number of primary CRC bytes generated by first CRC generator/checker (601); and, a second CRC generator/checker (603) which uses the primary CRC bytes and K1 number of its own generated verification CRC bytes to check the user data after retrieval from memory (602) and prior to encoding. In addition, second CRC generator/checker (603) can optionally apply K2-K1 number of its verification CRC bytes to encoder (604) for use as secondary CRC bytes. The number of CRC bytes K1 and K2 actually outputted by the respective CRC generator/checkers (601,603) is programmable. |
