Figure 4-20, Instruction set attributes register 1 format -27 – ARM Cortex R4F User Manual

Page 111

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System Control Coprocessor

ARM DDI 0363E

Copyright © 2009 ARM Limited. All rights reserved.

4-27

ID013010

Non-Confidential, Unrestricted Access

To access the Instruction Set Attributes Register 0, read CP15 with:

MRC p15, 0, <Rd>, c0, c2, 0 ; Read Instruction Set Attributes Register 0

c0, Instruction Set Attributes Register 1, ISAR1

The Instruction Set Attributes Register 1 provides information about the instruction set that the
processor supports beyond the basic set.

The Instruction Set Attributes Register 1 is:

a read-only register

accessible in Privileged mode only.

Figure 4-20 shows the bit arrangement for Instruction Set Attributes Register 1.

Figure 4-20 Instruction Set Attributes Register 1 format

[11:8]

Bitfield instructions

Indicates support for bitfield instructions.

0x1

, the processor supports bitfield instructions,

BFC

,

BFI

,

SBFX

, and

UBFX

.

[7:4]

Bit counting instructions

Indicates support for bit counting instructions.

0x1

, the processor supports

CLZ

.

[3:0]

Atomic instructions

Indicates support for atomic load and store instructions.

0x1

, the processor supports

SWP

and

SWPB

.

Table 4-14 Instruction Set Attributes Register 0 bit functions (continued)

Bits Field

Function

31

28 27

24 23

20 19

16 15

12 11

8 7

4 3

0

Jazelle instructions

Interworking instructions

Immediate instructions

ITE instructions

Extend instructions

Exception 2 instructions

Exception 1 instructions

Endian instructions

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