3.7 MVFR2, Media and VFP Feature Register 2

The MVFR2 describes the features provided by the AArch32 Advanced SIMD and floating-point implementation.

Bit field descriptions

MVFR2 is a 32-bit register.

Figure 3-5 MVFR2 bit assignments
To view this graphic, your browser must support the SVG format. Either install a browser with native support, or install an appropriate plugin such as Adobe SVG Viewer.


[31:8]
res0Reserved.
FPMisc, [7:4]

Indicates support for miscellaneous VFP features.

0x4

Supports:

  • Floating-point selection.
  • Floating-point Conversion to Integer with Directed Rounding modes.
  • Floating-point Round to Integral Floating-point.
  • Floating-point MaxNum and MinNum.
SIMDMisc, [3:0]

Indicates support for miscellaneous Advanced SIMD features.

0x3

Supports:

  • Floating-point Conversion to Integer with Directed Rounding modes.
  • Floating-point Round to Integral Floating-point.
  • Floating-point MaxNum and MinNum.
Configurations

MVFR2 is architecturally mapped to AArch64 register MVFR2_EL1. See 2.7 MVFR2_EL1, Media and VFP Feature Register 2, EL1.

There is one copy of this register that is used in both Secure and Non-secure states.

Usage constraints

Accessing the MVFR2

To access the MVFR2:

VMRS <Rt>, MVFR2 ; Read MVFR2 into Rt

Register access is encoded as follows:

Table 3-7 MVFR2 access encoding

spec_reg
0101
Accessibility
This register is accessible as follows:

EL0

(NS)

EL0

(S)

EL1

(NS)

EL1

(S)

EL2

EL3

(SCR.NS = 1)

EL3

(SCR.NS = 0)

- - Config RO Config Config RO

Access to this register depends on the values of CPACR.{cp10,cp11}, NSACR.{cp10,cp11}, HCPTR.{TCP10,TCP11}, and FPEXC.EN. For details of which values of these fields allow access at which Exception levels, see the Arm® Architecture Reference Manual Armv8, for Armv8-A architecture profile.

MVFR2 must be interpreted with MVFR0 and MVFR1. See 3.5 MVFR0, Media and VFP Feature Register 0 and 3.6 MVFR1, Media and VFP Feature Register 1.

Non-ConfidentialPDF file icon PDF version100446_0200_00_en
Copyright © 2016–2018 Arm Limited or its affiliates. All rights reserved.