The programmer can determine whether or not a processor supports the APIC architecture by executing a CPUID request type 1 and verifying that the EDX[APIC] bit = 1 (see Figure 61-7 on page 1509).
Assuming that the APIC is supported, the version of the APIC implementation may be determined by reading the Local APIC's Version Register. It has the format illustrated in Figure 61-8 on page 1510 and contains the following information:
The number of entries in the Local APIC's Local Vector Table (LVT). See “The Local Vector Table” on page 1539 for more information.
The version (i.e., type of) Local APIC.
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