5.4.2 Accessing the FPU registers

Access to the FPU registers is controlled by the CPACR. To use the FPU, you must define the CPACR and Floating-Point Exception Register (FPEXC) registers to enable the FPU.

To use the FPU, you must define the CPACR and Floating-Point Exception Register (FPEXC) registers to enable the FPU:

Procedure

  1. Set the CPACR for access to CP10 and CP11 (the FPU coprocessors):
    LDR r0, =(0xF << 20)
    MCR p15, 0, r0, c1, c0, 2
  2. Set the FPEXC EN bit to enable the FPU:
    MOV r3, #0x40000000 VMSR FPEXC, r3
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