UM0438 datasheet(46/50 Pages) STMICROELECTRONICS

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Glossary

UM0438

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Exponent

In the binary representation of a floating-point number, the exponent is the component that

normally signifies the integer power to which the value two is raised in determining the value

of the represented number. See also Biased exponent.

General-purpose register (GPR)

Any of the 32 registers in the general-purpose register file. These registers provide the

source operands and destination results for all integer data manipulation instructions.

Integer load instructions move data from memory to GPRs and store instructions move data

from GPRs to memory.

IEEE 754

A standard written by the Institute of Electrical and Electronics Engineers that defines

operations and representations of binary floating-point arithmetic.

Inexact

Loss of accuracy in an arithmetic operation when the rounded result differs from the

infinitely precise value with unbounded range.

Least-significant bit (lsb) The bit 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.

Mnemonic

The abbreviated name of an instruction used for coding.

Modulo

A value v which lies outside the range of numbers representable by an n-bit wide destination

type is replaced by the low-order n bits of the two’s complement representation of v.

Most-significant bit (msb)

The highest-order bit in an address, registers, data element, or instruction encoding.

NaN

An abbreviation for ‘Not a Number’; a symbolic entity encoded in floating-point format. There

are two types of NaNs—signaling NaNs (SNaNs) and quiet NaNs (QNaNs).

UM0438 Datasheet(PDF) 46 Page - STMicroelectronics