RTEMS PowerPC Applications Supplement
All times reported in this chapter were measured using the PowerPC Instruction Simulator (PSIM). PSIM simulates a variety of PowerPC 6xx models with the PPC603e being used as the basis for the measurements reported in this chapter.
The PowerPC decrementer register was was used to gather all timing information. In real hardware implementations of the PowerPC architecture, this register would typically count something like CPU cycles or be a function of the clock speed. However, with PSIM each count of the decrementer register represents an instruction. Thus all measurements in this chapter are reported as the actual number of instructions executed. All sources of hardware interrupts were disabled, although traps were enabled and the interrupt level of the PowerPC allows all interrupts.
RTEMS PowerPC Applications Supplement
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