In the construction of Gray codes, sequences of binary values with the property that consecutive sequence values differ from each other in a single bit position, a number can be converted into the Gray code value at position of the sequence simply by taking the exclusive or of and ( the number formed by shifting right by a single bit position ).
32.
Unlike an arithmetic shift, a logical shift does not preserve a number's sign bit or distinguish a number's exponent from its significand ( mantissa ); every bit in the operand is simply moved a given number of bit positions, and the vacant bit-positions are filled, usually with zeros ( contrast with a circular shift ).
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There were also four locations in core memory, at addresses 20-23, dubbed " editing locations " because whatever was stored there would emerge shifted or rotated by one bit position, except for one that shifted right seven bit positions, to extract one of the seven-bit interpretive op . codes that were packed two to a word.
34.
There were also four locations in core memory, at addresses 20-23, dubbed " editing locations " because whatever was stored there would emerge shifted or rotated by one bit position, except for one that shifted right seven bit positions, to extract one of the seven-bit interpretive op . codes that were packed two to a word.
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The resulting 48-bit identifier uniquely identifies the assignee of the IAB and provides 4096 unique EUI-48 numbers for use by the organization that purchased the IAB . The assignee may create unique identifiers by concatenating a 12-bit extension identifier that is assigned by the organization that purchases the IAB in the bit positions occupied by the 12 additional bits mentioned previously.
36.
The literal / Literal set of variables can be seen as a " pseudo-bit-tree " similar to a bit-tree but with 3 variables instead of 1 in every node, chosen depending on the " literal _ bit _ mode " value at the bit position of the next bit to decode after the bit-tree context denoted by the node.
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To construct the binary-reflected Gray code iteratively, at step 0 start with the code _ 0 = 0, and at step i > 0 find the bit position of the least significant 1 in the binary representation of i and flip the bit at that position in the previous code \ mathrm { code } _ { i-1 } to get the next code code _ i.
38.
For both types of sequences, the last bit is flipped and an implicit-1 should be added directly below the MSB . When the + 1 from the two's complement negation for p7 in bit position 0 ( LSB ) and all the-1's in bit columns 7 through 14 ( where each of the MSBs are located ) are added together, they can be simplified to the single 1 that " magically " is floating out to the left . For an explanation and proof of why flipping the MSB saves us the sign extension, see a computer arithmetic book.
39.
An example of a single-bit error that would be ignored by a system with no error-checking, would halt a machine with parity checking, or would be invisibly corrected by ECC : a single bit is stuck at 1 due to a faulty chip, or becomes changed to 1 due to background or cosmic radiation; a spreadsheet storing numbers in ASCII format is loaded, and the character " 8 " ( decimal value 56 in the ASCII encoding ) is stored in the byte that contains the stuck bit at its lowest bit position; then, a change is made to the spreadsheet and it is saved.
40.
"literal _ bit _ mode " is an array of 8 values in the 0-2 range, one for each bit position in a byte, which are 1 or 2 if the previous packet was a * MATCH and it is either the most significant bit position or all the more significant bits in the literal to encode / decode are equal to the bits in the corresponding positions in " match _ byte ", while otherwise it is 0; the choice between the 1 or 2 values depends on the value of the bit at the same position in " match _ byte ".
