...the world's most energy friendly microcontrollers
2014-07-02 - Tiny Gecko Family - d0034_Rev1.20
113
www.silabs.com
Bit
Name
Reset
Access
Description
Value
Mode
Description
0
HFCLK
HFPERCLK = HFCLK.
1
HFCLK2
HFPERCLK = HFCLK/2.
2
HFCLK4
HFPERCLK = HFCLK/4.
3
HFCLK8
HFPERCLK = HFCLK/8.
4
HFCLK16
HFPERCLK = HFCLK/16.
5
HFCLK32
HFPERCLK = HFCLK/32.
6
HFCLK64
HFPERCLK = HFCLK/64.
7
HFCLK128
HFPERCLK = HFCLK/128.
8
HFCLK256
HFPERCLK = HFCLK/256.
9
HFCLK512
HFPERCLK = HFCLK/512.
11.5.4 CMU_HFRCOCTRL - HFRCO Control Register
Offset
Bit Position
0x00C
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reset
0x00
0x3
0x80
Access
RW
RW
RW
Name
Bit
Name
Reset
Access
Description
31:17
Reserved
To ensure compatibility with future devices, always write bits to 0. More information in Section 2.1 (p. 3)
16:12
SUDELAY
0x00
RW
HFRCO Start-up Delay
Always write this field to 0.
11
Reserved
To ensure compatibility with future devices, always write bits to 0. More information in Section 2.1 (p. 3)
10:8
BAND
0x3
RW
HFRCO Band Select
Write this field to set the frequency band in which the HFRCO is to operate. When changing this setting there will be no glitches on
the HFRCO output, hence it is safe to change this setting even while the system is running on the HFRCO. To ensure an accurate
frequency, the HFTUNING value should also be written when changing the frequency band. The calibrated tuning value for the
different bands can be read from the Device Information page.
Value
Mode
Description
0
1MHZ
1 MHz band. NOTE: Also set the TUNING value (bits 7:0) when changing band.
1
7MHZ
7 MHz band. NOTE: Also set the TUNING value (bits 7:0) when changing band.
2
11MHZ
11 MHz band. NOTE: Also set the TUNING value (bits 7:0) when changing band.
3
14MHZ
14 MHz band. NOTE: Also set the TUNING value (bits 7:0) when changing band.
4
21MHZ
21 MHz band. NOTE: Also set the TUNING value (bits 7:0) when changing band.
5
28MHZ
28 MHz band. NOTE: Also set the TUNING value (bits 7:0) when changing band.
7:0
TUNING
0x80
RW
HFRCO Tuning Value
Writing this field adjusts the HFRCO frequency (the higher value, the higher frequency). This field is updated with the production
calibrated value for the 14 MHz band during reset, and the reset value might therefore vary between devices.
Summary of Contents for EFM32TG
Page 543: ......