NUMICRO-SDK Nuvoton Technology Corporation of America, NUMICRO-SDK Datasheet - Page 205

• Manufacturer Part Number: NUMICRO-SDK
• Description: KIT EVAUATION NUC100/120/130/140
• Manufacturer: Nuvoton Technology Corporation of America
• Series: NuMicro™r
• Type: MCUr

Specifications of NUMICRO-SDK

• Contents: Board, Cable, CD, Nu-Link
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: NUC100, NUC120, NUC130, NUC140

Clock Source Select Control Register 0 （CLKSEL0）
Register
CLKSEL0
Bits
[31:6]
[5:3]
[2:0]
31
23
15
7
Reserved
NuMicro™ NUC100 Series Technical Reference Manual
Offset
CLK_BA+0x10
Descriptions
Reserved
STCLK_S
HCLK_S
30
22
14
6
R/W
R/W
Reserved
Cortex_M0 SysTick clock source select (write-protection bits)
If SYST_CSR[2]=0, SysTick uses listed clock source below
These bits are protected bit. It means programming this bit needs to write “59h”, “16h”,
“88h” to address 0x5000_0100 to disable register protection. Reference the register
REGWRPROT at address GCR_BA+0x100.
000 = Clock source from external 4~24 MHz crystal clock
001 = Clock source from external 32.768 kHz crystal clock
010 = Clock source from external 4~24 MHz crystal clock/2
011 = Clock source from HCLK/2
1xx = Clock source from internal 22.1184 MHz oscillator clock/2
HCLK clock source select (write-protection bits)
1.
2.
3.
000 = Clock source from external 4~24 MHz crystal clock
001 = Clock source from external 32.768 kHz crystal clock
010 = Clock source from PLL clock
011 = Clock source from internal 10 kHz oscillator clock
1xx = Clock source from internal 22.1184 MHz oscillator clock
29
21
13
5
Before clock switching, the related clock sources (both pre-select and new-
select) must be turn on
The 3-bit default value is reloaded from the value of CFOSC (Config0[26:24]) in
user configuration register of Flash controller by any reset. Therefore the default
value is either 000b or 111b.
These bits are protected bit, It means programming this bit needs to write “59h”,
“16h”, “88h” to address 0x5000_0100 to disable register protection. Reference
the register REGWRPROT at address GCR_BA+0x100.
Description
Clock Source Select Control Register 0
STCLK_S
28
20
12
4
- 205 -
Reserved
Reserved
Reserved
27
19
11
3
Publication Release Date: Oct 22, 2010
26
18
10
2
HCLK_S
9
1
25
17
Revision V1.06
Reset Value
0x0000_003X
8
0
24
16