1.5.2 Typographic notationThe following typographic notation is used throughout this document:Example Descriptionplaceholder, x Items in italics are placeholders for information that you provide. Italicized text is also used forthe titles of publications and for emphasis. Plain lowercase letters are also used asplaceholders for single letters and numbers.code Fixed-width type indicates text that must be typed exactly as shown. It is used for instructionmnemonics, directives, symbols, subcommands, parameters, and operators. Fixed-width typeis also used for example code. Instruction mnemonics and directives in text and tables areshown in all caps; for example, BSR.SR[SCM] A mnemonic in brackets represents a named field in a register. This example refers to theScaling Mode (SCM) field in the Status Register (SR).REVNO[6:4], XAD[7:0] Numbers in brackets and separated by a colon represent either:• A subset of a register's named fieldFor example, REVNO[6:4] refers to bits 6–4 that are part of the COREREV field thatoccupies bits 6–0 of the REVNO register.• A continuous range of individual signals of a busFor example, XAD[7:0] refers to signals 7–0 of the XAD bus.1.5.3 Special termsThe following terms have special meanings:Term Meaningasserted Refers to the state of a signal as follows:• An active-high signal is asserted when high (1).• An active-low signal is asserted when low (0).deasserted Refers to the state of a signal as follows:• An active-high signal is deasserted when low (0).• An active-low signal is deasserted when high (1).In some cases, deasserted signals are described as negated.reserved Refers to a memory space, register, field, or programming setting. Writes to a reserved location canresult in unpredictable functionality or behavior.• Do not modify the default value of a reserved programming setting, such as the reset value ofa reserved register field.• Consider undefined locations in memory to be reserved.w1c Write 1 to clear: Refers to a register bitfield that must be written as 1 to be "cleared."Chapter 1 PrefaceMPC5777C Reference Manual Addendum, Rev. 1, 12/2015Freescale Semiconductor, Inc. 9
