Method and apparatus for implementing a type 8B6T encoder and decoder

• US 5,525,983 A
• Filed: 05/25/1994
• Issued: 06/11/1996
• Est. Priority Date: 05/25/1994
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Patel, Sandeep, Johnson, Howard W., Rivers, J. R.
• Primary Examiner(s): Hoff, Marc S.
• Application Number:
  US08/248,934
• Time in Patent Office: 748 Days
• Field of Search: 341/57, 341/58, 341/59, 341/106
• US Class Current: 341/57
• CPC Class Codes: H03M 5/18 two levels being symmetrical with respect to the third level, i.e. balanced bipolar ternary code
• CPC Class Codes: H04L 25/4925 using balanced bipolar ternary codes

Abstract

An apparatus and method for transmitting an 8-bit binary format data word as a 6-trit ternary code word includes an encoder, a decoder, and a code assignment that produce, for each 8-bit data word value, an unique 6-trit ternary code word that is particularly optimized for transmission over twisted-pair cable. The logic circuitry of the invention is optimized to accomplish the translation using a small number of combinatorial logic gates. The present invention thus has advantages in size, speed and performance over other possible means for encoding an 8 bit data word to a 6 trit code word.

Claims

1. An encoder/transmitter for 8B-6T code conversion, comprising:

means for receiving an 8-bit binary data word;

combinatorial logic means capable of converting each possible 8-bit binary data word to an unique 12-bit binary-coded-ternary (BCT) code word, operatively connected to;

a circuit for selecting an inverted code word for every other code word that has an algebraic weight of +1 in a series of code words, operatively connected to;

means for separating said 12-bit code word into subparts operatively connected to;

a signal generator for producing a serial ternary data stream in response to said subparts.

2. The encoder according to claim 1, wherein said unique 12-bit binary-coded-ternary (BCT) code word is representative of a 6-trit ternary code word and wherein each 6-trit ternary code word has an algebraic weight of either 0 or +1 and has no more than three leading or trailing zeros.

3. The encoder according to claim 1, wherein said combinatorial logic means is additionally capable of detecting when the algebraic weight of a 12-bit BCT code word is +1 and generating a signal when the algebraic weight of a 12-bit BCT code word is +1.

13. The encoder according to claims 1, 2, or 3, the decoder according to claim 4, the apparatus according to claims 5 or 6, and the system according to claim 11, wherein said combinatorial logic is operative to convert between 8-bit binary data words and 6-trit ternary code words according to the following table:

space="preserve" listing-type="tabular">______________________________________ Binary Ternary ______________________________________ 00000000 - + 0 0 - + 00000001 0 - + - + 0 00000010 0 - + 0 - + 00000011 0 - + + 0 - 00000100 - + 0 + 0 - 00000101 + 0 - - + 0 00000110 + 0 - 0 - + 00000111 + 0 - + 0 - 00001000 - + 0 0 + - 00001001 0 - + + - 0 00001010 0 - + 0 + - 00001011 0 - + - 0 + 00001100 - + 0 - 0 + 00001101 + 0 - + - 0 00001110 + 0 - 0 + - 00001111 + 0 - - 0 + 00010000 0 - - + 0 + 00010001 - 0 - 0 + + 00010010 - 0 - + 0 + 00010011 - 0 - + + 0 00010100 0 - - + + 0 00010101 - - 0 0 + + 00010110 - - 0 + 0 + 00010111 - - 0 + + 0 00011000 - + 0 - + 0 00011001 + - 0 - + 0 00011010 - + + - + 0 00011011 + 0 0 - + 0 00011100 + 0 0 + - 0 00011101 - + + + - 0 00011110 + - 0 + - 0 00011111 - + 0 + - 0 00100000 - + + - 0 0 00100001 + 0 0 + - - 00100010 - + 0 - + + 00100011 + - 0 - + + 00100100 + - 0 + 0 0 00100101 - + 0 + 0 0 00100110 + 0 0 - 0 0 00100111 - + + + - - 00101000 0 + + - 0 - 00101001 + 0 + 0 - - 00101010 + 0 + - 0 - 00101011 + 0 + - - 0 00101100 0 + + - - 0 00101101 + + 0 0 - - 00101110 + + 0 - 0 - 00101111 + + 0 - - 0 00110000 + - 0 0 - + 00110001 0 + - - + 0 00110010 0 + - 0 - + 00110011 0 + - + 0 - 00110100 + - 0 + 0 - 00110101 - 0 + - + 0 00110110 - 0 + 0 - + 00110111 - 0 + + 0 - 00111000 + - 0 0 + - 00111001 0 + - + - 0 00111010 0 + - 0 + - 00111011 0 + - - 0 + 00111100 + - 0 - 0 + 00111101 - 0 + + - 0 00111110 - 0 + 0 + - 00111111 - 0 + - 0 + 01000000 - 0 0 + 0 + 01000001 0 - 0 0 + + 01000010 0 - 0 + 0 + 01000011 0 - 0 + + 0 01000100 - 0 0 + + 0 01000101 0 0 - 0 + + 01000110 0 0 - + 0 + 01000111 0 0 - + + 0 01001000 0 0 + 0 0 0 01001001 + + - 0 0 0 01001010 + - + 0 0 0 01001011 - + + 0 0 0 01001100 0 + - 0 0 0 01001101 + 0 - 0 0 0 01001110 0 - + 0 0 0 01001111 - 0 + 0 0 0 01010000 + - - + 0 + 01010001 - + - 0 + + 01010010 - + - + 0 + 01010011 - + - + + 0 01010100 + - - + + 0 01010101 - - + 0 + + 01010110 - - + + 0 + 01010111 - - + + + 0 01011000 - - 0 + + + 01011001 - 0 - + + + 01011010 0 - - + + + 01011011 0 - - 0 + + 01011100 + - - 0 + + 01011101 - 0 0 0 + + 01011110 0 + + + - - 01011111 0 + + - 0 0 01100000 0 + + 0 - 0 01100001 + 0 + - 0 0 01100010 + 0 + 0 - 0 01100011 + 0 + 0 0 - 01100100 0 + + 0 0 - 01100101 + + 0 - 0 0 01100110 + + 0 0 - 0 01100111 + + 0 0 0 - 01101000 0 + + - + - 01101001 + 0 + + - - 01101010 + 0 + - + - 01101011 + 0 + - - + 01101100 0 + + - - + 01101101 + + 0 + - - 01101110 + + 0 - + - 01101111 + + 0 - - + 01110000 0 0 0 + + - 01110001 0 0 0 + - + 01110010 0 0 0 - + + 01110011 0 0 0 + 0 0 01110100 0 0 0 + 0 - 01110101 0 0 0 + - 0 01110110 0 0 0 - 0 + 01110111 0 0 0 - + 0 01111000 + + + - - 0 01111001 + + + - 0 - 01111010 + + + 0 - - 01111011 0 + + 0 - - 01111100 - 0 0 - + + 01111101 - 0 0 + 0 0 01111110 + - - - + + 01111111 + - - + 0 0 10000000 - 0 0 + - + 10000001 0 - 0 - + + 10000010 0 - 0 + - + 10000011 0 - 0 + + - 10000100 - 0 0 + + - 10000101 0 0 - - + + 10000110 0 0 - + - + 10000111 0 0 - + + - 10001000 - 0 0 0 + 0 10001001 0 - 0 + 0 0 10001010 0 - 0 0 + 0 10001011 0 - 0 0 0 + 10001100 - 0 0 0 0 + 10001101 0 0 - + 0 0 10001110 0 0 - 0 + 0 10001111 0 0 - 0 0 + 10010000 + - - + - + 10010001 - + - - + + 10010010 - + - + - + 10010011 - + - + + - 10010100 + - - + + - 10010101 - - + - + + 10010110 - - + + - + 10010111 - - + + + - 10011000 + - - 0 + 0 10011001 - + - + 0 0 10011010 - + - 0 + 0 10011011 - + - 0 0 + 10011100 + - - 0 0 + 10011101 - - + + 0 0 10011110 - - + 0 + 0 10011111 - - + 0 0 + 10100000 - + + 0 - 0 10100001 + - + - 0 0 10100010 + - + 0 - 0 10100011 + - + 0 0 - 10100100 - + + 0 0 - 10100101 + + - - 0 0 10100110 + + - 0 - 0 10100111 + + - 0 0 - 10101000 - + + - + - 10101001 + - + + - - 10101010 + - + - + - 10101011 + - + - - + 10101100 - + + - - + 10101101 + + - + - - 10101110 + + - - + - 10101111 + + - - - + 10110000 + 0 0 0 - 0 10110001 0 + 0 - 0 0 10110010 0 + 0 0 - 0 10110011 0 + 0 0 0 - 10110100 + 0 0 0 0 - 10110101 0 0 + - 0 0 10110110 0 0 + 0 - 0 10110111 0 0 + 0 0 - 10111000 + 0 0 - + - 10111001 0 + 0 + - - 10111010 0 + 0 - + - 10111011 0 + 0 - - + 10111100 + 0 0 - - + 10111101 0 0 + + - - 10111110 0 0 + - + - 10111111 0 0 + - - + 11000000 - + 0 + - + 11000001 0 - + - + + 11000010 0 - + + - + 11000011 0 - + + + - 11000100 - + 0 + + - 11000101 + 0 - - + + 11000110 + 0 - + - + 11000111 + 0 - + + - 11001000 - + 0 0 + 0 11001001 0 - + + 0 0 11001010 0 - + 0 + 0 11001011 0 - + 0 0 + 11001100 - + 0 0 0 + 11001101 + 0 - + 0 0 11001110 + 0 - 0 + 0 11001111 + 0 - 0 0 + 11010000 + - 0 + - + 11010001 0 + - - + + 11010010 0 + - + - + 11010011 0 + - + + - 11010100 + - 0 + + - 11010101 - 0 + - + + 11010110 - 0 + + - + 11010111 - 0 + + + - 11011000 + - 0 0 + 0 11011001 0 + - + 0 0 11011010 0 + - 0 + 0 11011011 0 + - 0 0 + 11011100 + - 0 0 0 + 11011101 - 0 + + 0 0 11011110 - 0 + 0 + 0 11011111 - 0 + 0 0 + 11100000 - + + 0 - + 11100001 + - + - + 0 11100010 + - + 0 - + 11100011 + - + + 0 - 11100100 - + + + 0 - 11100101 + + - - + 0 11100110 + + - 0 - + 11100111 + + - + 0 - 11101000 - + + 0 + - 11101001 + - + + - 0 11101010 + - + 0 + - 11101011 + - + - 0 + 11101100 - + + - 0 + 11101101 + + - + - 0 11101110 + + - 0 + - 11101111 + + - - 0 + 11110000 + 0 0 0 - + 11110001 0 + 0 - + 0 11110010 0 + 0 0 - + 11110011 0 + 0 + 0 - 11110100 + 0 0 + 0 - 11110101 0 0 + - + 0 11110110 0 0 + 0 - + 11110111 0 0 + + 0 - 11111000 + 0 0 0 + - 11111001 0 + 0 + - 0 11111010 0 + 0 0 + - 11111011 0 + 0 - 0 + 11111100 + 0 0 - 0 + 11111101 0 0 + + - 0 11111110 0 0 + 0 + - 11111111 0 0 + - 0 + ______________________________________

14. The encoder according to claims 1, 2, or 3, the decoder according to claim 4, the apparatus according to claims 5 or 6, or the system according to claim 11, wherein translation between each ternary trit and its binary representation is according to the following table:

space="preserve" listing-type="tabular">______________________________________ Binary Ternary ______________________________________ 00 - 01 0 10 0 11 + ______________________________________

15. The encoder according to claims 1, 2, or 3, the apparatus according to claims 5, or the system according to claim 11, wherein said combinatorial logic for converting each possible 8-bit binary data word having binary digits B7-B0 to a unique 12-bit binary-coded-ternary (BCT) code word having binary digits T11-T0 is constructed such that its 12 bit output is a function of its 8 bit input according to the following logical relationships:

space="preserve" listing-type="tabular">______________________________________ m1 = B7 * B5 * !B4;

m2 = !B7 * !B6 * B5 * B4;

m3 = !B7 * !B6 * !B5 * !B4;

m4 = !B7 * B6 * !B5 * B4 * !B3;

m5 = B7 * !B6 * !B5 * B4;

m6 = B7 * B6 * !B5 * !B4;

m7 = B7 * B6 * !B5 *B4;

p1 = B2 * (B1 + B0);

p2 = !B2 * (B1 + B0);

p3 = !B1 * !B0;

s1 = !B7 * !B6 * !B5 * !B4 * !B3;

s2 = !B7 * !B6 * !B5 * !B4 * B3;

s3 = B7 * !B6 * !B5 * !B3;

s4 = B7 * B6 * !B5 * !B3;

s5 = !B7 * !B6 * B5 * B4 * !B3;

s6 = !B7 * !B6 *B5 * B4 * B3;

s7 = !B7 * B6 * B5 * !B4 * B3;

s8 = B7 * !B6 * B5 * B3;

s9 = B7 * B6 * B5 * !B3;

s10 = B7 * B6 * B5 * B3;

t1 = (B1 * B0) + (B2 * !B1 * !B0);

t2 = !B1 * B0;

t3 = (!B2 * !B1 * !B0) + (B1 * !B0);

u1 = B1 + B0;

u2 = B2 + (!B1 * !B0);

v1 = B1 + !B0;

v2 = B0 + (B2 * !B1);

special = (!B7 * !B6 * !B5 * B4 * B3) + (!B7 * !B6 * B5 * !B4 * !B3) + (!B7 * B6 * !B5 * B3) + (!B7 * B6 * B5 * B4);

T10 = (((u1 * !B4) + (!u1 * B4)) * !special) + (!B7 * ! B6 * !B5 * B4 * B3 * ((!B2 * B0) + (B2 * !B0))) + (!B7 * !B6 * B5 * !B4 * !B3 * ((!B2 * B0) + (B2 * !B0))) + (!B7 * B6 * !B5 * !B4 * B3 * ((!B1 * B0) + (B1 * !B0))) + (!B7 * B6 * !B5 * B4 * B3 * ((!B2 * B1) + (B2 * !B1 * !B0))) + (!B7 * B6 * B5 * B4 * B3 * ((!B2 * !B1) + (B1 * !B0) + (B2 * B1)));

T8 = (((u2 * !B4) + (!u2 * B4)) * !special) + (!B7 * !B6 * !B5 * B4 * B3 * ((!B2 * !B0) + (B2 * B0))) + (!B7 * !B6 * B5 * !B4 * !B3 * ((! B2 * !B0) + (B2 * B0))) + (!B7 * B6 * !B5 * !B4 * B3 * ((!B2 * B0) + (B2 * !B1))) + (!B7 * B6 * !B5 * B4 * B3 * ((!B1 * B0) + (B2 * B1))) + (!B7 * B6 * B5 * B4 * B3 * !(B2 * B1));

T6 = (((!B4 * (!B10 + !B8)) + (B4 * !B10 * !B8)) * !special) + (!B7 * !B6 * !B5 * B4 * B3 * ((!B2 * !B0) + (B2 * B0))) + (!B7 * !B6 * B5 * !B4 * !B3 * ((!B2 * !B0) + (B2 * B0))) + (!B7 * B6 * !B5 * !B4 * B3 * (B1 + (!B2 * !B0))) + (!B7 * B6 * !B5 * B4 * B3 * ((B2 * B0) + (B2 * B1) + (!B2 * !B1 * !B0))) + (!B7 * B6 * B5 * B4 * B3 * !(B2 * B1));

T4 = (((v1 * !B3) + (!v1 * B3)) * !special) + (!B7 * !B6 * !B5 * B4 * B3 * B2) + (!B7 * !B6 * B5 * !B4 * !B3 * ((B2 * !B1) + (B2 * B0) + (!B1 * B0))) + (!B7 * B6 * !B5 * B4 * B3 * ((!B2 * !B1) + (B1 * !B0))) + (!B7 * B6 * B5 * B4 * !B3 * (!B1 + (!B2 * B0))) + (!B7 * B6 * B5 * B4 * B3 * ((B2 * B0) + (!B2 * B1)));

T2 = (((v2 * !B3) + (!v2 * B3)) * !special) + (!B7 * !B6 * !B5 * B4 * B3 * !B2) + (!B7 * !B6 * B5 * !B4 * !B3 * !((B2 * !B1) + (B2 * B0) + (!B1 * B0))) + (!B7 * B6 * !B5 * B4 * B3 * !(B2 * B1 * !B0)) + (!B7 * B6 * B5 * B4 * !B3 * ((!B2 * !B0) + (B2 * B1 * B0) + (!B1 * !B0))) + (!B7 * B6 * B5 * B4 * B3 * ((B2 * !B0) + (!B2 * !B1 * B0))) T0 = (((!B3 * (!B2 + !B4)) + (B3 * !B4 * !B2)) * !special) + (!B7 * !B6 * !B5 * B4 * B3 * !B2) + (!B7 * !B6 * B5 * !B4 * !B3 * !((B2 * !B1) + (B2 * B0) + (!B1 * B0))) + (!B7 * B6 * !B5 * B4 * B3 * !(B2 * B1 * !B0)) + (!B7 * B6 * B5 * B4 * !B3 * ((B2 * B1) + (!B2 * !B1 * B0) + (B1 * !B0))) + (!B7 * B6 * B5 * B4 * B3 * ((B2 * !B0) + (!B1 * !B0)));

T11 = (B5 * !(m1 * p3) * !(m2 * p1) * !(!B7 * !B6 * B5 * !B4 * !B3 * ((B2 * B0) + (!B2 * !B0))) * !(!B7 * B6 * B5 * B4 * B3 * (B2 * B1))) + (m3 * p1) + (m4 * p3) + (m5 * p3) + (m6 * p1) + (m7 * !p1) + (!B7 * !B6 * !B5 * B4 * B3 * ((!B2 * B0) + (B2 * !B0))) + (!B7 * B6 * !B5 * !B4 * B3 * (!B1 + (!B2 * !B0))) + (!B7 * B6 * !B5 * B4 * B3 * ((B2 * B1) + (B2 * !B0)));

T9 = (B5 * !(m1 * p2) * !(m2 * p3) * !(!B7 * !B6 * B5 * !B4 * !B3 * ((!B2 * B1 * B0) + (B2 * !B1 *!B0))) * !(!B7 * B6 * B5 * B4 * B3 * B2)) + (m3 * p3) + (m4 * p2) + (m5 * p2) + (m6 * p3) + (m7 * !p3) + (!B7 * !B6 * !B5 * B4 * B3 * !((!B2 * !B1 * B0) + (B2 * B1 * !B0))) + (!B7 * B6 * !B5 * !B4 * B3 * ((!B1 * !B0) + (B1 * B0) + (!B2 * B0))) + (!B7 * B6 * !B5 * B4 * B3 * B2 * B1);

T7 = (B5 * !(m1 * p1) * !(m2 * p2) * !(!B7 * !B6 * B5 * !B4 * !B3 * ((!B2 * B1 * !B0) + (B2 * !B1 * B0))) * !(!B7 * B6 * B5 * B4 * B3 * B2)) + (m3 * p2) + (m4 * p1) + (m5 * p1) + (m6 * p2) + (m7 * !p2) + (!B7 * !B6 * !B5 * B4 * B3 * !((!B2 * !B1 * !B0)-↑

§

↑

§

G.sup.⊥

+ (B2 * B1 * B0))) + (!B7 * B6 * !B5 * !B4 * B3 * (B1 + (!B2 * !B0))) + (!B7 * B6 * !B5 * B4 * B3 * B2 * B1);

T5 = (!B5 * !(s1 * !t1) * !(s2 * t1) * !(s3 * t2) * !(s4 * t2) * !(!B7 * !B6 * !B5 * B4 * B3 * !B2) * !(!B7 * B6 * !B5 * B4 * B3 * B2 * B1 * B0)) + (s5 * t1) + (s6 * !t1) + (s7 * t2) + (s8 * t2) + (s9 * t1) + (s10 * !t1) + (!B7 * !B6 * B5 * !B4 * !B3 * ((!B1 * B0) + (B2 * !B1) + (B2 * B0))) + (!B7 * B6 * B5 * B4 * !B3 * (!B1 + (!B2 * B0))) + (!B7 * B6 * B5 * B4 * B3 * B2 * B0);

T3 = (!B5 * !(s1 * !t2) * !(s2 * t2) * !(s3 * t3) * !(s4 * t3) * !(!B7 * !B6 * !B5 * B4 * B3 * B2) * !(!B7 * B6 * !B5 * B4 * B3 * B2 * B1) ) + (s5 * t2) + (s6 * !t2) + (s7 * t3) + (s8 * t3) + (s9 * t2) + (s10 * !t2) + (!B7 * !B6 * B5 * !B4 * !B3 * ((!B2 * B1) + (B2 * !B1))) + (!B7 * B6 * B5 * B4 * !B3 * (B1 + (!B2 * !B0))) + (!B7 * B6 * B5 * B4 * B3 * B2);

T1 = (!B5 * !(s1 * !t3) * !(s2 * t3) * ! (s3 * t1) * !(s4 * t1) * !(!B7 * !B6 * !B5 * B4 * B3 * !B2) * !(!B7 * B6 * !B5 * B4 * B3 * B2 * B1)) + (s5 * t3) + (s6 * !t3) + (s7 * t1) + (s8 * t1) + (s9 * t3) + (s10 * !t3) + (!B7 * !B6 * B5 * !B4 * !B3 * ((!B2 * B1) + (B2 * !B1))) + (!B7 * B6 * B5 * B4 * !B3 * ((!B1 * B0) + (B1 * !B0) (!B2 * B1))) + (!B7 * B6 * B5 * B4 * B3 * B2). ______________________________________

4. A decoder/receiver for 6T-8B code conversion, comprising:

a ternary detector which produces a 2-bit binary signal in response to each digit in a serial ternary pulse data stream received on a channel operatively connected to;

means for assembling a 12-bit binary-coded-ternary (BCT) code word for each six ternary trits received operatively connected to;

an algebraic weight detecting circuit for detecting when the algebraic weight of a 12-bit BCT code word is -1 operatively connected to;

a circuit for selecting an inverted code word for every code word that has an algebraic weight of -1, operatively connected to;

a combinatorial logic means for converting each 12-bit binary-coded-ternary (BCT) code word to an 8-bit binary data word.

5. Apparatus for encoding eight bit binary data words into six trit ternary code words comprising:

receiver means for receiving the binary data word;

combinatorial logic encoder means coupled to the receiver means, for producing encoded data capable of being converted into ternary code words;

said ternary code words having no more than a first preselected number of leading or trailing zeros;

said ternary code words having an algebraic weight of zero or plus one.

6. Apparatus for decoding six trit ternary code words into eight bit binary data comprising:

receiver means for receiving the 6 trit code words;

ternary to binary conversion circuit for converting each trit of said 6 trit code words into a binary representation for assembling into a binary coded ternary word;

said ternary code words having no more than a first preselected number of leading or trailing zeros;

said ternary code words having an algebraic weight of zero or plus one; and

combinatorial logic decoder means for converting the ternary code words into binary data words.

7. The apparatus according to claim 6 wherein said representation is two binary bits and wherein said binary coded ternary word is a 12-bit word.

8. A method for encoding an eight bit binary data word into a six trit ternary code word, said method comprising the steps of:

receiving the binary data word; and

converting said binary data word to a binary coded ternary code word data word using combinatorial logic;

said binary coded ternary code word being capable of being converted into ternary code words;

said ternary code words having no more than a first preselected number of leading or trailing zeros;

said ternary code words having an algebraic weight of zero or plus one.

10. The method according to claims 8 or 9 wherein converting between 8 bit binary data words and 6-trit ternary code words produces results in accordance with the following table:

space="preserve" listing-type="tabular">______________________________________ Binary Ternary ______________________________________ 00000000 - + 0 0 - + 00000001 0 - + - + 0 00000010 0 - + 0 - + 00000011 0 - + + 0 - 00000100 - + 0 + 0 - 00000101 + 0 - - + 0 00000110 + 0 - 0 - + 00000111 + 0 - + 0 - 00001000 - + 0 0 + - 00001001 0 - + + - 0 00001010 0 - + 0 + - 00001011 0 - + - 0 + 00001100 - + 0 - 0 + 00001101 + 0 - + - 0 00001110 + 0 - 0 + - 00001111 + 0 - - 0 + 00010000 0 - - + 0 + 00010001 - 0 - 0 + + 00010010 - 0 - + 0 + 00010011 - 0 - + + 0 00010100 0 - - + + 0 00010101 - - 0 0 + + 00010110 - - 0 + 0 + 00010111 - - 0 + + 0 00011000 - + 0 - + 0 00011001 + - 0 - + 0 00011010 - + + - + 0 00011011 + 0 0 - + 0 00011100 + 0 0 + - 0 00011101 - + + + - 0 00011110 + - 0 + - 0 00011111 - + 0 + - 0 00100000 - + + - 0 0 00100001 + 0 0 + - - 00100010 - + 0 - + + 00100011 + - 0 - + + 00100100 + - 0 + 0 0 00100101 - + 0 + 0 0 00100110 + 0 0 - 0 0 00100111 - + + + - - 00101000 0 + + - 0 - 00101001 + 0 + 0 - - 00101010 + 0 + - 0 - 00101011 + 0 + - - 0 00101100 0 + + - - 0 00101101 + + 0 0 - - 00101110 + + 0 - 0 - 00101111 + + 0 - - 0 00110000 + - 0 0 - + 00110001 0 + - - + 0 00110010 0 + - 0 - + 00110011 0 + - + 0 - 00110100 + - 0 + 0 - 00110101 - 0 + - + 0 00110110 - 0 + 0 - + 00110111 - 0 + + 0 - 00111000 + - 0 0 + - 00111001 0 + - + - 0 00111010 0 + - 0 + - 00111011 0 + - - 0 + 00111100 + - 0 - 0 + 00111101 - 0 + + - 0 00111110 - 0 + 0 + - 00111111 - 0 + - 0 + 01000000 - 0 0 + 0 + 01000001 0 - 0 0 + + 01000010 0 - 0 + 0 + 01000011 0 - 0 + + 0 01000100 - 0 0 + + 0 01000101 0 0 - 0 + + 01000110 0 0 - + 0 + 01000111 0 0 - + + 0 01001000 0 0 + 0 0 0 01001001 + + - 0 0 0 01001010 + - + 0 0 0 01001011 - + + 0 0 0 01001100 0 + - 0 0 0 01001101 + 0 - 0 0 0 01001110 0 - + 0 0 0 01001111 - 0 + 0 0 0 01010000 + - - + 0 + 01010001 - + - 0 + + 01010010 - + - + 0 + 01010011 - + - + + 0 01010100 + - - + + 0 01010101 - - + 0 + + 01010110 - - + + 0 + 01010111 - - + + + 0 01011000 - - 0 + + + 01011001 - 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9. A method for decoding a six trit ternary code word into an eight bit binary data word, said method comprising the steps of:

receiving the ternary code word;

producing a binary coded ternary code word capable of being converted into a binary data word;

said binary coded ternary code word representing a ternary code word having no more than a first preselected number of leading or trailing zeros;

said binary coded ternary code word representing a ternary code word having an algebraic weight factor of zero or plus one; and

converting said binary coded ternary code word to a binary data word using combinatorial logic.

12. The system according to claim 9 wherein said subparts are two binary bits and wherein said ternary code word is a 12-bit word.

11. A system for transmitting binary data between a transmitter and a receiver comprising:

means for receiving a sequence of 8-bit binary data words from a transmitter;

combinatorial logic means for converting said 8-bit data words into binary coded ternary code words with an algebraic weight of 0 or 1;

means for DC balancing a sequence of said code words by inverting every second code word that has an algebraic weight of 1 thereby producing an inverted code word with an algebraic weight of -1;

means for converting subparts of said code word into a ternary pulse;

a medium for transmitting said ternary pulses to said receiver;

means at said receiver for detecting said ternary pulses and generating a binary representation for each detected pulse;

means for assembling said binary representation codes into a received binary coded ternary code word;

means for inverting each said received code word that has an algebraic weight of -1; and

combinatorial logic means for converting each said received code word to a received 8-bit binary data word and making said received data word available to said receiver.

16. The decoder according to claim 4, the apparatus according to claim 6, or the system according to claim 11, wherein said combinatorial logic circuit for converting each input 12-bit binary-coded-ternary data word having binary digits T11-T0 to an output 8-bit binary data word having binary digits B7-B0 is constructed such that its 8-bit output is a function of its 12-bit input according to the following logical relationships:

space="preserve" listing-type="tabular">______________________________________ al = T11 * T9 * T7;

ar = T5 * T3 * T1;

bl = !T11 * !T9 * !T7;

br = !T5 * !T3 * !T1;

cl = (T10 * !T8 * !T6) + (!T10 * T8 * !T6) + (!T10 * !T8 * T6);

cr = (T4 * !T2 * !T0) + (!T4 * T2 * !T0) + (!T4 * !T2 * T0);

dl = (!T10 * T8 * T6) + (T10 * !T8 * T6) + (T10 * T8 * !T6);

dr = (!T4 * T2 * T0) + (T4 * !T2 * T0) + (T4 * T2 * !T0);

el = (!T11 * T9 * T8 * T7) + (T11 * !T9 * T7 * T6) + (T11 * T10 * T9 * !T7);

er = (!T5 * T3 * T2 * T1) + (T5 * !T3 * T1 * T0) + (T5 * T4 * T3 * !T1);

fl = (T11 * !T9 * !T8 * !T7) + (!T11 * T9 * !T7 * !T6) + (!T11 * !T10 * !T9 * T7);

fr = ( T5 * !T3 * !T2 * !T1) + (!T5 * T3 * !T1 * !T0) + (!T5 * !T4 * !T3 * T1);

lp0 = (T11 * T10 * !T9 * !T8 * T7 * !T6) + (T11 * !T10 * T9 * T8 * !T7 * !T6) + (!T11 * !T10 * T9 * !T8 * T7 * T6);

rp0 = (T5 * T4 * !T3 * !T2 * T1 * !T0) + (T5 * !T4 * T3 * T2 * !T1 * !T0) + (!T5 * !T4 * T3 * !T2 * T1 * T0);

ln0 = (!T11 * !T10 * T9 * T8 * !T7 * T6) + (!T11 * T10 * !T9 * !T8 * T7 * T6) + (T11 * T10 * !T9 * T8 * !T7 * !T6);

rn0 = (!T5 * !T4 * T3 * T2 * !T1 * T0) + (!T5 * T4 * !T3 * !T2 * T1 * T0) + (T5 * T4 * !T3 * T2 * !T1 * !T0);

lp1 = (al * cl) + e1;

rp1 = (ar * cr) + er;

ln1 = (bl * dl) + f1;

rn1 = (br * dr) + fr;

lp2 = al * dl;

rp2 = ar * dr;

ln2 = bl * cl;

rn2 = br * cr;

lp3 = T10 * T8 * T6;

rp3 = T4 * T2 * T0;

l0hat = !T10 * !T8 * !T6;

r0hat = !T4 * !T2 * !T0;

x10 = (T10 * !cl) + (!T10 * cl) x8 = (T8 * !cl) + (!T8 * cl);

x4 = (T4 * !cr) + (!T4 * cr);

x2 = (T2 * !cr) + (!T2 * cr);

special = (l0hat + r0hat + lp3 + rp3 + ( !T10 * T8 * T6 * !T4 * T2 * T0) + (!T10 * T8 * T6 * T4 * !T2 * !T0) + (T10 * !T8 * !T6 * !T4 * T2 * T0) + ( T10 * !T8 * !T6 * T4 * !T2 * !T0));

B7 = ((lp1 + rp1) * !(l0hat + r0hat)) * !special;

B6 = (((lp0 + 1n0 + l0hat) * rp1) + (1n1 * rp2) + (1n2 * rp3) + ((rp0 + rn0 + r0hat) * lp1) + (rn1 * lp2) + (rn2 * lp3)) * !special + special * !(((rp0 + rn0) * !l0hat) + (lp1 * rn1) + ((1n0 + lp0) * rp1));

B5 = ((lp0 * !rp1) + lp1 + lp2 + lp3) * special + special * (((T9 + T7) * rp1) + (lp1 * rn1) + l0hat + (lp2 * rn2) + (1n1 * !rp2) + lp3);

B4 = (cl * !special) + special * !( ((ln0 + lp0) * rp1) + (lp1 *rn1) + r0hat);

B3 = (cr * !special) + special * !( ((ln0 + lp0) * rp1) + (lp1 * rn1) + l0hat);

B2 = (((x10 * x8) + (!x10 * x2)) * !special) + special * (rp0 + (l0hat * rn0) + ((lp0 + ln0) * rp1 * T5) + (lp0 * r0hat) + (ln0 * r0hat) + (lp2 ! * !(!T5 * T4)) + (rp2 * !(!T11 * T10)) + (ln1 * rp1) + (lp1 * rn1 * ((T6 * T5) + (!T6 * !T5))));

B1 = (((x10 * x4) + (!x10 * !x4)) * !special) + special * ((lp1 * rn0) + (rp0 * !(T9 * T7)) + (rp1 * ((!T6 * !T4) + (!T7 * !T6 * T5) + (!T11 * T9 * !T5))) + (rn1 * ((T6 * T5) + (!T6 * !T5) + (T11 * !T10))) + (r0hat * (T6 * !(T11 * T9))) + (ln2 * !T8 * !T6) + (rn2 * !T2 * !T0) + (l0hat * ((T3 T1) + (!T5 * !T1))));

B0 = (((x10 * x2) + (!x10 * !x4)) * !special) + special * ((rn0 * T11 * !T5) + (rp0 * (!T11)) + (T5 * T4 * !T3 * !T2 * !T1 * !T0 * !(T11 * T10)) + (rp1 * ((!T0 * !T7) + (T7 * !T5 * !T9))) + (r0hat * ((T11 * T10 * T8) + (!T11 * !T10 * T7))) + (ln2 * (!T4 + T8)) + (rp2 * T6) + (lp2 * !T4) + (l0hat * (!T2 * T4)) + (rn2 * (T2 + !T10))). ______________________________________