ADSL encoder and decoder

An ADSL encoder processing digital data including at least one data bit and a sub-carrier for transmitting data of 3 bits, the ADSL encoder comprising:

• a digital signal processor outputting the digital data;
• a buffer storing plural data bits of the digital data output from the digital signal processor in sequence;
• a bit extractor receiving the data bits from the buffer one byte by one byte, and shifting the 3 bits of data to an extracted data;
• and
• a constellation point mapper starting a constellation point mapping operation corresponding to the extracted data based on the 3 bits of data, and
• wherein the constellation point mapping operation comprises:
• processing an AND operation of an inverse of a highest bit and a second highest bit in the extracted data obtaining a first result, and processing an AND operation of the highest bit and the inverse of a third highest bit obtaining a second result, then processing an OR operation of the first result and the second result obtaining a value defined as a first temporary bit;
• processing an AND operation of the inverse of the highest bit and the third highest bit in the extracted data obtaining a third result, and processing an AND operation of the highest bit and the second highest bit obtaining a fourth result, then processing an OR operation of the third result and the fourth result obtaining a value defined as a second temporary bit;
• shifting the extracted data one bit toward right;
• setting the first temporary bit as the highest bit of the extracted data, and setting the second temporary bit as the second highest bit of the extracted data;
• filling out one byte of a vertical axis data in sequence, starting from the lowest bit of the extracted data, and then every other bit, the rest of the vertical axis data are filled out with the second highest bit of the extracted data;
• and
• filling out one byte of a horizontal axis data in sequence, starting from the second lowest bit of the extracted data, and then every other bit, the rest of the horizontal axis data are filled out with the highest bit of the extracted data.

An ADSL encoder processing digital data including at least one data bit and a sub-carrier for transmitting data of odd bits having a value greater than 3, the ADSL encoder comprising:

• a digital signal processor outputting the digital data;
• a buffer storing plural data bits of the digital data output from the digital signal processor in sequence;
• a bit extractor receiving the data bits from the buffer one byte by one byte, and shifting the odd bits of data that are greater than 3 to an extracted data;
• and
• a constellation point mapper starting a constellation point mapping operation corresponding to the extracted data based on the odd bits of data that are greater than 3, and
• wherein the constellation point mapping operation comprises:
• processing an OR operation of an inverse of a highest bit, an inverse of a third highest bit and a fourth highest bit in the extracted data obtaining a first OR operation result, and processing an AND operation of the first OR operation result and a second highest bit obtaining a first result;
• processing an AND operation of the highest bit, the inverse of the third highest bit and the fourth highest bit obtaining a second result;
• processing an OR operation of the first result and the second result obtaining a value defined as a first temporary bit;
• processing an OR operation of the inverse of the highest bit and the second highest bit obtaining a second OR operation result, and processing an AND operation of the second OR operation result and the third highest bit obtaining a third result;
• processing an OR operation of the second highest bit and the third highest bit in the extracted data obtaining a third OR operation result, and processing an AND operation of the highest bit and a fifth highest bit obtaining a fourth result;
• processing an OR operation of the third result and the fourth result obtaining a value defined as a second temporary bit;
• processing an OR operation of the inverse of the highest bit, the inverse of the third highest bit and the inverse of the fourth highest bit obtaining a fourth OR operation result, and processing an AND operation of the fourth OR operation result and the second highest bit obtaining a fifth result;
• processing an AND operation of the highest bit, the inverse of the third highest bit and the inverse of the fourth highest bit obtaining a sixth result;
• processing an OR operation of the fifth result and the sixth result obtaining a value defined as a third temporary bit;
• processing an OR operation of the inverse of the highest bit and the second highest bit obtaining a fifth OR operation result, and processing an AND operation of the fifth OR operation result and the third highest bit obtaining a seventh result;
• processing an OR operation of the second highest bit and the third highest bit obtaining a sixth OR operation result, and processing an AND operation of the highest bit, the sixth OR operation result and the inverse of the fifth highest bit obtaining an eighth result;
• processing an OR operation of the seventh result and the eighth result obtaining a value defined as a fourth temporary bit;
• shifting the extracted data one bit toward right;
• setting up the first temporary bit as a defined highest bit of the extracted data;
• setting up the second temporary bit as a defined second highest bit of the extracted data;
• setting up the third temporary bit as a defined third highest bit of the extracted data;
• setting up the fourth temporary bit as a defined fourth highest bit of the extracted data;
• filling out one byte of a vertical axis data in sequence, starting from the lowest bit of the extracted data, and then every other bit, the rest of the vertical axis data are filled out with the second highest bit of the extracted data;
• and
• filling out one byte of a horizontal axis data in sequence, starting from the second lowest bit of the extracted data, and then every other bit, the rest of the horizontal axis data are filled out with the highest bit of the extracted data.