Device for comparing two words of n bits each

Device for comparing two words N and P of n bits each, which includes at least one level-1 comparator block which itself includes:

• n basic comparator blocks, each enabling the bits Ni and Pi of position i of words N and P to be compared, with i being between 0 and n-1, and each including:
• a first sub-block for generating at its output, forming a first output of the basic comparator block, a first signal indicating whether or not the bits Ni and Pi are equal;
• a second sub-block enabling a second signal, indicating which of the bits Ni and Pi is greater, to be generated at its output;
• and
• a third sub-block enabling the second signal to pass to a second output of the basic comparator block, if the first signal does not indicate an equality of the bits Ni and Pi, and otherwise enabling the second signal to be blocked;
• a circuit which generates a third signal at a first output of the level-1 comparator block, indicating that the numbers N and P are equal if the n first signals indicate that the n bits Ni and the n bits Pi are equal, and otherwise indicating that the numbers N and P are not equal;
• and
• a first selective passage gate enabling the second output of a basic comparator block to be selectively connected to a second output of the level-1 comparator block, which basic comparator block, from among the basic comparator blocks having a second signal at their second output, processes higher-order bits, with the signal present at the second output of the level-1 comparator block indicating which of the numbers N and P is greater.

A method of comparing two words N and P of n bits each, the method comprising:

• comparing the bits Ni and Pi of position i of words N and P, with i being between 0 and n-1, which comprises for each bit i:
• generating at a first output a first signal indicating whether or not the bits Ni and Pi are equal;
• generating a second signal indicating which of the bits Ni and Pi is greater;
• and
• passing the second signal to a second output if the first signal does not indicate an equality of the bits Ni and Pi, and otherwise blocking the second signal from being passed to the second output;
• generating a third signal at a first comparator output indicating that the numbers N and P are equal if the n first signals indicate that the n bits Ni and the n bits Pi are equal, and otherwise indicating that the numbers N and P are not equal;
• and
• selectively passing the second signals that are passed to respective second outputs to a second comparator output so as to indicate which of the numbers N and P is greater.