NUMICRO-SDK Nuvoton Technology Corporation of America, NUMICRO-SDK Datasheet - Page 194

• 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

5.3.6
This device is equipped a power-of-2 frequency divider which is composed by16 chained divide-
by-2 shift registers. One of the 16 shift register outputs selected by a sixteen to one multiplexer is
reflected to CLKO function pin. Therefore there are 16 options of power-of-2 divided clocks with
the frequency from F
The output formula is F
divider output frequency and N is the 4-bit value in FSEL (FRQDIV[3:0]).
When write 1 to DIVIDER_EN (FRQDIV[4]), the chained counter starts to count. When write 0 to
DIVIDER_EN (FRQDIV[4]), the chained counter continuously runs till divided clock reaches low
state and stay in low state.
Frequency Divider Output
FRQDIV_CLK
divide-by-2 counter
NuMicro™ NUC100 Series Technical Reference Manual
Enable
DIVIDER_EN
(FRQDIV[4])
in
1/2
/2
Figure 5-8 Block Diagram of Frequency Divider
Figure 5-7 Clock Source of Frequency Divider
1
out
to F
= F
1/2
in
/2
2
in
16
/2
where Fin is input clock frequency to the clock divider.
(N+1)
1/2
divide-by-2 counter
3
, where F
16 chained
- 194 -
…...
in
1/2
is the input clock frequency, F
15
Publication Release Date: Dec. 22, 2010
1/2
16
0000
0001
1110
1111
:
:
(FRQDIV[3:0])
16 to 1
FSEL
MUX
Revision V1.06
out
CLKO
is the clock