Identifying CPU: Difference between revisions
Jump to navigation
Jump to search
mNo edit summary |
mNo edit summary |
||
| Line 8: | Line 8: | ||
* Calculate the operating frequency of the CPU by timing the execution of a sequence of instructions. | * Calculate the operating frequency of the CPU by timing the execution of a sequence of instructions. | ||
== | ==External documentation== | ||
Intel describes the complete process of CPU identification in [http://www.intel.com/content/dam/www/public/us/en/documents/application-notes/processor-identification-cpuid-instruction-note.pdf Application Note 485]. | Intel describes the complete process of CPU identification in [http://www.intel.com/content/dam/www/public/us/en/documents/application-notes/processor-identification-cpuid-instruction-note.pdf Application Note 485]. | ||
AMD describes their specific CPUID implementation [http://support.amd.com/us/Embedded_TechDocs/25481.pdf here] | AMD describes their specific CPUID implementation [http://support.amd.com/us/Embedded_TechDocs/25481.pdf here] | ||
Revision as of 00:02, 15 August 2012
Introduction
Identifying an Intel-compatible x86 CPU is done in several steps :
- Check that we have a 32-bits 80386 minimum CPU.
- Check the presence of the CPUID instruction.
- If CPUID is supported, use the instruction to get CPU information and supported instructions.
- If CPUID is not supported, reset the CPU to get its signature.
- Calculate the operating frequency of the CPU by timing the execution of a sequence of instructions.
External documentation
Intel describes the complete process of CPU identification in Application Note 485.
AMD describes their specific CPUID implementation here