Cortex-R4 and Cortex-R4F Technical Reference ManualRevision: r1p4
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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

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Table 11.3 shows the FPSID bit assignments.

Table 11.3. FPSID Register bit assignments

BitsNameFunction

[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

[15:8]

Part number

0x31 = Cortex-R4F

[7:4]

Variant

0x4 = Cortex-R4F

[3:0]

Revision

When the build-configuration includes the floating point unit, this register identifies the revision number of the floating-point unit:

0x3 = r1p0

0x4 = r1p1

0x6 = r1p2

0x7 = r1p3

0x8 = r1p4

[a] For information about the Common VFP subarchitecture see the ARM Architecture Reference Manual.


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