System Control Coprocessor
ARM DDI 0301H Copyright © 2004-2009 ARM Limited. All rights reserved. 3-90
ID012310 Non-Confidential, Unrestricted Access
The Data TCM Region Register is:
•in CP15 c9
• a 32-bit read/write register common to Secure and Non-secure worlds
• accessible in privileged modes only.
If the processor is configured to have 2 Data TCMs, each TCM has a separate Data TCM Region
Register. The TCM Selection Register determines the register in use.
Figure 3-50 shows the bit arrangement for the Data TCM Region Register.
Figure 3-50 Data TCM Region Register format
Table 3-85 lists how the bit values correspond with the Data TCM Region Register functions.
Attempts to write to this register in Secure Privileged mode when CP15SDISABLE is HIGH
result in an Undefined exception, see TrustZone write access disable on page 2-9.
Note
When the NS access bit is 0 for Data TCM, see c9, Data TCM Non-secure Control Access
Register on page 3-93, attempts to access the Data TCM Region Register from the Non-secure
world cause an Undefined exception.
E
n
Base address (physical address)
31 12 11 7 6 2 1 0
SBZ/UNP Size
S
B
Z
Table 3-85 Data TCM Region Register bit functions
Bits Field name Function
[31:12] Base address Contains the physical base address of the TCM.
The base address must be aligned to the size of the TCM.
Any bits in the range [(log
2
(RAMSize)-1):12] are ignored. The base address is 0 at Reset.
[11:7] - UNP/SBZ.
[6:2] Size
Indicates the size of the TCM on reads
a
. All other values are reserved:
b00000 = 0KB
b00011 = 4KB
b00100 = 8KB
b00101 = 16KB
b00110 = 32KB.
[1] - UNP/SBZ.
[0] En Indicates if the TCM is enabled.
0 = TCM disabled, reset value
1 = TCM enabled.
a. On writes this field is ignored. For more details see Tightly-coupled memory on page 7-7.
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