Motorola DigitalDNA MPC180E User Manual page 99

L
Latency. The number of clock cycles necessary to execute an instruction and
make ready the results of that execution for a subsequent instruction.
Least-significant bit (lsb). The bit of least value in an address, register, data
element, or instruction encoding.
Least-significant byte (LSB). The byte of least value in an address, register,
data element, or instruction encoding.
Little-endian. A byte-ordering method in memory where the address n of a
word corresponds to the least-significant byte. In an addressed
memory word, the bytes are ordered (left to right) 3, 2, 1, 0, with 3
being the most-significant byte. See Big-endian.
M
Masking. Hiding internal interrupts and signals from the external interface
via control registers.
MD4. Message Digest 4. Hashing algorithm developed by Rivest which
processes a series of 512-bit message blocks and produces a single
128-bit Hash representing the original message.
MD5. Message Digest 5. Hashing algorithm developed by Rivest which pads
(if necessary) the message to be hashed to create a 512 bit block. This
block is compressed by XOR-ing two inputs: the 512-bit message
block, and a 128-bit key. Stronger than MD.
MDEU. Message Digest Execution Unit. A device or silicon block which
accelerates the hashing functions associated with message
authentication.
Memory-mapped accesses. Accesses whose addresses use the page or block
address translation mechanisms provided by the MMU and that
occur externally with the bus protocol defined for memory.
Message Authentication Code (MAC). A MAC is a function that takes a
variable length input and a key to produce a fixed-length output. See
also hash-based MAC, stream-cipher based MAC, and block-cipher
based MAC.
Message Digest. The result of applying a hash function to a message.
Modular arithmetic. A form of arithmetic where integers are considered
equal if they leave the same remainder when divided by the modulus.
Modulus. The integer used to divide out by in modular arithmetic.
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Glossary Glossary-5