| 摘要 |
PURPOSE:To find out simply a defective sector by applying retrial when a CRC error is generated and checking whether the number of retrials coincident with a permissible error number. CONSTITUTION:If a CRC error is caused by the 1st access of a sector, the sector number is stored in a register 5 and if the 2nd CRC error is generated in a sector having the said CRC error succeedingly, the content of registers 6, 7 is the sector number generating the said CRC error. Then if it is discriminated that the 3rd CRC error is generated, since the content of the registers 5, 6, 7 is all equal, it is discriminated whether or not the permissible error number set in a register 8 is equal to the retrial number counted in a counter register 9. When ''Yes'', the sector is recognized as a defective sector. Thus, it is recognized instantly which sector is the defective sector. |
