ARM ARM1176JZF-S User Manual

System Control Coprocessor
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3.2.9 c1, Coprocessor Access Control Register
The purpose of the Coprocessor Access Control Register is to set access rights for the
coprocessors CP0 through CP13. This register has no effect on access to CP14, the debug
control coprocessor, or CP15, the system control coprocessor. This register also provides a
means for software to determine if any particular coprocessor, CP0-CP13, exists in the system.
The Coprocessor Access Control Register is:
•in CP15 c1
• a 32-bit read/write register common to Secure and Non-secure worlds
• accessible in privileged modes only.
Figure 3-28 shows the arrangement of bits in the register.
Figure 3-28 Coprocessor Access Control Register format
Table 3-44 lists how the bit values correspond with the Coprocessor Access Control Register
functions.
Access to coprocessors in the Non-secure world depends on the permissions set in the c1,
Non-Secure Access Control Register on page 3-55.
Attempts to read or write the Coprocessor Access Control Register access bits depend on the
corresponding bit for each coprocessor in c1, Non-Secure Access Control Register on page 3-55.
Table 3-45 lists the results of attempted access to coprocessor access bits for each mode.
To use the Coprocessor Access Control Register read or write CP15 with:
• Opcode_1 set to 0
SBZ/UNP
31 28 27 26 25 24 23
22
21
20 19 18
17
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
cp13 cp12 cp11 cp10 cp9 cp8 cp7 cp6 cp5 cp4 cp3 cp2 cp1 cp0
Table 3-44 Coprocessor Access Control Register bit functions
Bits Field name Function
[31:28] - UNP/SBZ.
-
cp<n>
a
Defines access permissions for each coprocessor.
Access denied is the reset condition.
Access denied is the behavior for non-existent coprocessors:
b00 = Access denied, reset value. Attempted access generates an Undefined exception
b01 = Privileged mode access only
b10 = Reserved.
b11 = Privileged and User mode access.
a. n is the coprocessor number between 0 and 13.
Table 3-45 Results of access to the Coprocessor Access Control Register
Corresponding bit in Non-Secure
Access Control Register
Secure Privileged Non-secure Privileged
User
Read Write Read Write
0 Data Data b00 Ignored Undefined exception
1 Data Data Data Data Undefined exception

ARM ARM1176JZF-S Specifications

General

Brand	ARM
Model	ARM1176JZF-S
Category	Computer Hardware
Language	English