User’s Manual
IBM PowerPC 750GX and 750GL RISC Microprocessor
Page 20 of 377
gx_preface.fm.(1.2)
March 27, 2006
Conventions Used in This Manual
Notational Conventions
mnemonics Instruction mnemonics are shown in lowercase bold.
italics Italics indicate variable command parameters. For example: bcctrx. Book titles in text are
set in italics.
0x0 Prefix to denote a hexadecimal number.
0b0 Prefix to denote a binary number.
crfD Instruction syntax used to identify a destination Condition Register (CR) field.
rA, rB Instruction syntax used to identify a source General Purpose Register (GPR).
rD Instruction syntax used to identify a destination GPR.
frA, frB, frC Instruction syntax used to identify a source Floating Point Register (FPR).
frD Instruction syntax used to identify a destination FPR.
REG[FIELD] Abbreviations or acronyms for registers are shown in uppercase text. Specific bits, fields,
or ranges appear in brackets. For example, MSR[LE] refers to the little-endian mode
enable bit in the Machine State Register.
x In certain contexts, such as a signal encoding, this indicates a don’t care.
n Used to express an undefined numerical value.
¬
NOT logical operator.
& AND logical operator.
| OR logical operator.
Indicates reserved bits or bit fields in a register. Although these bits can be written to as
either ones or zeros, they are always read as zeros.
0 0 0 0