System Control Coprocessor
ARM DDI 0301H Copyright © 2004-2009 ARM Limited. All rights reserved. 3-6
ID012310 Non-Confidential, Unrestricted Access
Some of the functionality depends on how you set external signals at reset.
System control and configuration behaves in three ways:
• as a set of flags or enables for specific functionality
• as a set of numbers, values that indicate system functionality
• as a set of addresses for processes in memory.
3.1.3 MMU control and configuration
The purpose of the MMU control and configuration registers is to:
• allocate physical address locations from the Virtual Addresses (VAs) that the processor
generates.
• control program access to memory.
• designate areas of memory as either:
— noncacheable
— unbufferable
— noncacheable and unbufferable.
• detect MMU faults and external aborts
• hold thread and process IDs
• provide direct access to the TLB lockdown entries.
The MMU control and configuration registers consist of one 32-bit read-only register, one 32-bit
write-only register, and 22 32-bit read/write registers. Figure 3-2 on page 3-7 shows the
arrangement of registers in this functional group.