LM3S2110 Datasheet, PDF (60/485 Pages) List of Unclassifed Manufacturers – Microcontroller

System Control
1. Bypass the PLL and system clock divider by setting the BYPASS bit and clearing the USESYS
bit in the RCC register. This configures the system to run off a “raw” clock source (using the
main oscillator or internal oscillator) and allows for the new PLL configuration to be validated
before switching the system clock to the PLL.
2. Select the crystal value (XTAL) and oscillator source (OSCSRC), and clear the PWRDN bit in
RCC/RCC2. Setting the XTAL field automatically pulls valid PLL configuration data for the
appropriate crystal, and clearing the PWRDN bit powers and enables the PLL and its output.
3. Select the desired system divider (SYSDIV) in RCC/RCC2 and set the USESYS bit in RCC. The
SYSDIV field determines the system frequency for the microcontroller.
4. Wait for the PLL to lock by polling the PLLLRIS bit in the Raw Interrupt Status (RIS) register.
5. Enable use of the PLL by clearing the BYPASS bit in RCC/RCC2.
6.3 Register Map
Table 6-1 on page 60 lists the System Control registers, grouped by function. The offset listed is a
hexadecimal increment to the register’s address, relative to the System Control base address of
0x400F.E000.
Note: Spaces in the System Control register space that are not used are reserved for future or
internal use by Luminary Micro, Inc. Software should not modify any reserved memory
address.
Table 6-1. System Control Register Map
Offset Name
Type
Reset
Description
0x000 DID0
0x004 DID1
0x008 DC0
0x010 DC1
0x014 DC2
0x018 DC3
0x01C DC4
0x030 PBORCTL
0x034 LDOPCTL
0x040 SRCR0
0x044 SRCR1
0x048 SRCR2
0x050 RIS
0x054 IMC
0x058 MISC
0x05C RESC
RO
RO
RO
RO
RO
RO
RO
R/W
R/W
R/W
R/W
R/W
RO
R/W
R/W1C
R/W
-
-
0x003F.001F
0x0110.709F
0x0707.1011
0x0F00.B7C3
0x0000.00FF
0x0000.7FFD
0x0000.0000
0x00000000
0x00000000
0x00000000
0x0000.0000
0x0000.0000
0x0000.0000
-
Device Identification 0
Device Identification 1
Device Capabilities 0
Device Capabilities 1
Device Capabilities 2
Device Capabilities 3
Device Capabilities 4
Brown-Out Reset Control
LDO Power Control
Software Reset Control 0
Software Reset Control 1
Software Reset Control 2
Raw Interrupt Status
Interrupt Mask Control
Masked Interrupt Status and Clear
Reset Cause
See
page
62
78
80
81
83
85
87
64
65
106
107
109
66
67
68
69
60
November 29, 2007
Preliminary