FPU Programmers Model
ARM DDI 0363G Copyright © 2006-2011 ARM Limited. All rights reserved. 11-5
ID073015 Non-Confidential
All hardware ID information is privileged access only:
FPSID is privileged access only
This is a change in VFPv3 compared to VFPv2.
MVFR registers are privileged access only
User code must issue a system call to determine the features that are supported.
The following sections describe the VFP system registers:
• Floating-Point System ID Register
• Floating-Point Status and Control Register, FPSCR on page 11-6
• Floating-Point Exception Register, FPEXC on page 11-8
• Media and VFP Feature Registers, MVFR0 and MVFR1 on page 11-8.
11.3.1 Floating-Point System ID Register
The FPSID Register characteristics are:
Purpose Indicates which VFP implementation is being used.
Usage constraints The FPSID Register:
• is a read-only register
• must be accessed in Privileged mode only.
Configurations Use this register if the device is configured as a Cortex-R4F processor.
Attributes See Table 11-3.
Figure 11-2 shows the FPSID bit assignments.
Figure 11-2 FPSID Register bit assignments
Table 11-3 shows the FPSID bit assignments.
HW
Sub architecture Variant Revision
4
Implementer Part number
31 24 23 22 16 15 8 7 4 3 0
Table 11-3 FPSID Register bit assignments
Bits Name Function
[31:24] Implementer ARM Limited:
0x41
= A
[23] Hardware or software 0 = hardware implementation
[22:16] Subarchitecture version
VFP architecture v3 or later with Common VFP subarchitecture v2
a
:
0x02
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