4.3.23. c9, BTCM Region Register

The BTCM Region Register characteristics are:

Purpose
  • Holds the base address and size of the BTCM.

  • Determines if the BTCM is enabled.

Usage constraints

The BTCM Region Register is:

  • a read/write register

  • accessible in Privileged mode only.

Configurations

Available in all processor configurations.

Attributes

Figure 4.41 shows the BTCM Region Register bit assignments.

Figure 4.41. BTCM Region Register bit assignments

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Table 4.43 shows the BTCM Region Register bit assignments.

Table 4.43. BTCM Region Register bit assignments

Bits

Name

Function

 

[31:12]

Base address

Base address. Defines the base address of the BTCM. The base address must be aligned to the size of the BTCM. Any bits in the range [(log2(RAMSize)-1):12] are ignored.

At reset, if LOCZRAMAm is set to:

0 =The initial base address is 0x0.

1 =The initial base address is implementation-defined. See Configurable options.

[11:7]-UNP on reads, SBZ on writes.
[6:2]SizeSize. Indicates the size of the BTCM on reads. On writes this field is ignored. See About the TCMs.

b00000 = 0KB, no TCM

b00011 = 4KB

b00100 = 8KB

b00101 = 16KB

b00110 = 32KB

b00111 = 64KB

b01000 = 128KB

b01001 = 256KB

b01010 = 512kB

b01011 = 1MB

b01100 = 2MB

b01101 = 4MB

b01110 = 8MB

[1]-SBZ.

[0]

Enable

Enables or disables the BTCM.

0 = Disabled

1 = Enabled. The reset value of this field is determined by the INITRAMBm input pin.

This bit is RAZ if the processor has been implemented or integrated without a BTCM.


To access the BTCM Region Register, read or write CP15 with:

MRC p15, 0, <Rd>, c9, c1, 0  ; Read BTCM Region Register
MCR p15, 0, <Rd>, c9, c1, 0  ; Write BTCM Region Register
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