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Cortex-A8 Technical Reference Manual - ARM Information Center

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14.4 ETM register descriptions<br />

14.4.1 ID Register<br />

This section describes the following registers:<br />

• ID Register<br />

• Configuration Code Register on page 14-8<br />

• Configuration Code Extension Register on page 14-9<br />

• Peripheral Identification Registers on page 14-10<br />

• Component Identification Registers on page 14-11<br />

• Integration Test Registers on page 14-11.<br />

Embedded Trace Macrocell<br />

For more details about these registers and the other registers implemented by the ETM, see the<br />

Embedded Trace Macrocell Architecture Specification.<br />

The ID Register, at offset 0x1E4, is a 32-bit read-only register that provides information about<br />

the ETM architecture version and options supported. Figure 14-2 shows the bit arrangement of<br />

the ID Register.<br />

31 24 23 20 19 18 17 16 15 12 11 8 7 4 3 0<br />

0 1 0 0 0 0 0 1 0 0 0 0<br />

1 1 0 0 1 1 1 1 0 0 1 0 0 0 1 1 0 1 1 0<br />

Implementor<br />

Security Extensions support<br />

Thumb-2 support<br />

Reserved<br />

Load pc first<br />

<strong>ARM</strong> core<br />

family<br />

Major ETM<br />

architecture<br />

version<br />

Minor ETM<br />

architecture<br />

version<br />

Figure 14-2 ID Register format<br />

Table 14-3 shows how the bit values correspond with the ID Register functions.<br />

Bits Field Function<br />

[31:24] Implementor Indicates implementor, <strong>ARM</strong>:<br />

0x41.<br />

[23:20] - Reserved, RAZ.<br />

[19] Security Extensions<br />

support<br />

Revision<br />

Table 14-3 ID Register bit functions<br />

Indicates Security Extensions support. The processor supports Security Extensions<br />

architecture. If this bit is not set to 1, then the ETM behaves as if the processor is in<br />

secure state at all times.<br />

[18] Thumb-2 support All 32-bit Thumb instructions are traced as a single instruction, including BL and BLX<br />

immediate.<br />

[17] - Reserved, RAZ.<br />

[16] Load pc first All data transfers are traced in the same order that they appear in the <strong>ARM</strong> Architecture<br />

<strong>Reference</strong> <strong>Manual</strong>.<br />

[15:12] <strong>ARM</strong> core family Indicates the <strong>Cortex</strong>-<strong>A8</strong> processor.<br />

<strong>ARM</strong> DDI 0344K Copyright © 2006-2010 <strong>ARM</strong> Limited. All rights reserved. 14-7<br />

ID060510 Non-Confidential

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