2.6.4. Cortex-A9 voltage domains

The Cortex-A9 processor can have the following voltage domains:

Figure 2.4 shows the voltage domains.

Figure 2.4. Voltage domains for Cortex-A9 r2p0 designs

The FPU is part of the CPU power domain. The FPU clock is based on the CPU clock, There is static and dynamic high-level clock-gating:Neon SIMD data paths and logic are in a separate power domain, with dedicated clock and reset signals. There is static and dynamic high-level clock-gating:

When Neon is present, you can run FPU (non-SIMD) code without powering the SIMD part or clocking the SIMD part.

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