System Register Block
UG0331 User Guide Revision 15.0
695
22.3.21 M3 Configuration Register
Note:
Do not change these register fields dynamically for 005 and 010 devices, see
22.3.22 Fabric Interface Control (FIC) Register
Table 675 •
M3_CR
Bit
Number Name
Reset Value Description
[31:29]
Reserved
0
28
M3_MPU_DISABLE
0
When set, disables the memory protection unit (MPU) within the
Cortex-M3 processor.
[27:26]
STCLK_DIVISOR
0x3
Configures the amount of division to be performed on M3_CLK, in
order to generate the STCLK input for the Cortex-M3 processor.
This is used to control the frequency of STCLK.
00: M3_CLK/4
01: M3_CLK/8
10: M3_CLK/16
11: M3_CLK/32
[25:0]
STCALIB[25:0]
0x2000000
Used as the STCALIB input for the Cortex-M3 processor. It
determines the rollover value for the internal SysTick timer of the
Cortex-M3 processor. The bit definitions for this field are as follows:
STCALIB[25] – NOREF bit of SysTick Calibration Value Register; 1
indicates STCLK is not provided.
STCALIB[24] – SKEW bit of SysTick Calibration Value Register; 1
indicates calibration value is not exactly 10 ms.
STCALIB[23:0] – TENMS field of SysTick Calibration Value
Register; reload value to use for 10 ms timing.
Table 676 •
FAB_IF_CR
Bit
Number Name
Reset
Value
Description
[31:10]
Reserved
0
[9:4]
SW_FIC_REG_SEL
0x38
Indicates whether a specific fabric region is accessible by FIC_0 or
FIC_1. This register should not be changed during operation.
0: Fabric region associated with FIC_0
1: Fabric region associated with FIC_1
By default, fabric region 0, 1, 2 are accessible through FIC_0 and
regions 3, 4, 5 are accessible through FIC_1.
These bits are driven into the AHB bus in order to allocate a
specific memory region to either FIC_0 or FIC_1.
3
FAB1_AHB_MODE
0
Controls whether the FIC_1 fabric interface supports AHB mode or
APB mode. Allowed values:
0: Supports APB mode
1: Supports AHB mode
2
FAB0_AHB_MODE
0
Controls whether FIC_0 fabric interface supports AHB mode or
APB mode. Allowed values:
0: Supports APB mode
1: Supports AHB mode