2.8 FPEXC32_EL2, Floating-point Exception Control Register, EL2

The FPEXC32_EL2 provides access to the AArch32 register FPEXC from AArch64 state only. Its value has no effect on execution in AArch64 state.

Bit field descriptions

FPEXC32_EL2 is a 32-bit register.

Figure 2-6 FPEXC32_EL2 bit assignments
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EX, [31]

Exception bit.

res0The Cortex®-A55 core implementation does not generate asynchronous floating-point exceptions.
EN, [30]

Enable bit. A global enable for the Advanced SIMD and floating-point support:

0The Advanced SIMD and floating-point support is disabled. This is the reset value.
1The Advanced SIMD and floating-point support is enabled and operates normally.

This bit applies only to AArch32 execution, and only when EL1 is not AArch64.

FPEXC32_EL2 is architecturally mapped to AArch32 register FPEXC. See 3.8 FPEXC, Floating-Point Exception Control register.

Usage constraints

Accessing the FPEXC32_EL2

To access the FPEXC32_EL2:

MRS <Xt>, FPEXC32_EL2 ; Read FPEXC32_EL2 into Xt
              MSR FPEXC32_EL2, <Xt> ; Write Xt to FPEXC32_EL2

Register access is encoded as follows:

Table 2-8 FPEXC32_EL2 access encoding

op0 op1 CRn CRm op2
11 100 0101 0011 000
This register is accessible as follows:








(SCR.NS = 1)


(SCR.NS = 0)

- - - RW RW RW
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