User’s Manual

IBM PowerPC 750GX and 750GL RISC Microprocessor

register settings MSR, 162 SRR0/SRR1, 156

reset exception, 163

returning from an exception handler, 161 summary table, 152

system call exception, 171 terminology, 151

thermal management interrupt exception, 174 Execution synchronization, 90

Execution unit timing examples, 225 Execution units, 31

External control instructions, 117, 300

F

Features, list, 25

Finish cycle, definition, 210 Floating-Point Execution Models—UISA,83 Floating-point model

FE0/FE1 bits, 160

FP arithmetic instructions, 95 FP assist exceptions, 171 FP compare instructions, 97 FP multiply-add instructions, 96 FP operand, 84

FP rounding/conversion instructions, 96 FP store instructions, 105

FP unavailable exception, 171 FPSCR instructions, 97 IEEE-754 compatibility, 83 NI bit in FPSCR, 84

Floating-point unit execution timing, 232 latency, FP instructions, 242 overview, 31

Flush block operation, 143

FPRn (floating-point registers), 59

FPSCR (floating-point status and control register) FPSCR instructions, 97

FPSCR register description, 59

G

GBL (global) signal, 261

GPRn (general-purpose registers), 59

Guarded memory bit (G bit), 125

H, I, J, K

HIDn (hardware implementation-dependent) registers HID0

description, 65

doze bit, 337

DPM enable bit, 337 nap bit, 338

HID1 description, 70

PLL configuration, 277 HRESET (hard reset) signal, 272

IABR (instruction address breakpoint register), 64 ICTC (instruction cache throttling control) register, 77,

348

IEEE 1149.1-compliant interface, 319 Illegal instruction class, 88 Instruction cache

configuration, 124

instruction cache block fill operations, 139 organization, 125

Instruction cache throttling, 347 Instruction timing

examples cache hit, 220 cache miss, 223

execution unit, 225 instruction flow, 215

memory performance considerations, 235 terminology, 209

Instructions

branch address calculation, 106 branch instructions, 216, 226, 227 cache control instructions, 328 classes, 87

condition register logical, 107 defined instructions, 87 external control instructions, 117 floating-point

arithmetic, 95 compare, 97

FP rounding and conversion, 96 FP status and control register, 97 multiply-add,96

illegal instructions, 88 instruction cache throttling, 347 instruction flow diagram, 218 instruction serialization, 225 instruction serialization types, 225 instruction set summary, 86 integer

arithmetic, 92 compare, 93 logical, 94 rotate and shift, 95

integer instructions, 240

isync, instruction synchronization, 162 latency summary, 238

load and store address generation

floating-point,103

750gx_umIX.fm.(1.2)

Index

March 27, 2006

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