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Cortex-A8 Technical Reference Manual - ARM Information Center

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Table 3-57 shows the results of attempted access for each mode.<br />

To access the Secure Debug Enable Register, read or write CP15 with:<br />

MRC p15, 0, , c1, c1, 1 ; Read Secure Debug Enable Register<br />

MCR p15, 0, , c1, c1, 1 ; Write Secure Debug Enable Register<br />

3.2.30 c1, Nonsecure Access Control Register<br />

System Control Coprocessor<br />

Table 3-57 Results of access to the Secure Debug Enable Register a<br />

Secure privileged Nonsecure privileged Secure User Nonsecure User<br />

Read Write Read Write Read Write Read Write<br />

Data Data Undefined Undefined Undefined Undefined Undefined Undefined<br />

a. An entry of Undefined in the table means that the access gives an Undefined Instruction exception when the<br />

coprocessor instruction is executed.<br />

The purpose of the Nonsecure Access Control Register is to define the nonsecure access<br />

permission for:<br />

• coprocessors<br />

• internal PLE.<br />

Note<br />

This register has no effect on nonsecure access permissions for the debug control coprocessor,<br />

CP14, or the system control coprocessor, CP15.<br />

The Nonsecure Access Control Register is:<br />

• a read/write register in the Secure state<br />

• a read-only register in the Nonsecure state<br />

• only accessible in privileged modes.<br />

Figure 3-25 shows the bit arrangement of the Nonsecure Access Control Register.<br />

31 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0<br />

Reserved<br />

PLE<br />

TL<br />

CL<br />

Reserved<br />

CP13<br />

CP12<br />

CP11<br />

CP10<br />

CP9<br />

Figure 3-25 Nonsecure Access Control Register format<br />

<strong>ARM</strong> DDI 0344K Copyright © 2006-2010 <strong>ARM</strong> Limited. All rights reserved. 3-56<br />

ID060510 Non-Confidential<br />

CP0<br />

CP1<br />

CP2<br />

CP3<br />

CP4<br />

CP5<br />

CP6<br />

CP7<br />

CP8

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