Table 3-93 Tcm Selection Register Bit Functions; Figure 3-54 Tcm Selection Register Format - ARM ARM1176JZF-S Technical Reference Manual

MRC p15,0,<Rd>,c9,c1,3
MCR p15,0,<Rd>,c9,c1,3
3.2.29 c9, TCM Selection Register
Bits Field name
[31:2] -
[1:0] TCM number
ARM DDI 0301H
ID012310
Attempts to access the Instruction TCM Non-secure Control Access Register in modes other
than Secure Privileged result in an Undefined exception.
To use the Instruction TCM Non-secure Control Access Register read or write CP15 with:
• Opcode_1 set to 0
• CRn set to c9
• CRm set to c1
• Opcode_2 set to 3.
For example:
;Read Instruction TCM Non-secure Control Access Register
;Write Instruction TCM Non-secure Control Access Register
The purpose of the TCM Selection Register is to determine the bank of CP15 registers related
to TCM configuration in use. These banks consist of:
• c9, Data TCM Region Register on page 3-89
• c9, Instruction TCM Region Register on page 3-91
• c9, Data TCM Non-secure Control Access Register on page 3-93
• c9, Instruction TCM Non-secure Control Access Register on page 3-94.
The TCM Selection Register is:
• in CP15 c9
• a 32-bit read/write register banked in the Secure and Non-secure worlds
• accessible in privileged modes only.
Figure 3-54 shows the bit arrangement for the TCM Selection Register.
31
Table 3-93 lists how the bit values correspond with the TCM Selection Register functions.
Function
UNP/SBZ.
Selects the bank of CP15 registers related to TCM configuration. Attempts to select a bank
related to a TCM that does not exist are ignored:
b00 = TCM 0, reset value.
b01 = TCM 1. When there is only one TCM on both Instruction and Data sides, write access is
ignored.
b10 = Write access ignored.
b11 = Write access ignored.
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System Control Coprocessor
SBZ

Figure 3-54 TCM Selection Register format

Table 3-93 TCM Selection Register bit functions

2 1 0
TCM number
3-96