BAT32G1x9 user manual | Chapter 4 Clock generation circuit
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Rev.1.02
4.3.4
PLL Control Register (PLLCR) for System Clock
This is the register that the control system clock runs with the PLL. Set the PLLCR registers via the 8-bit
memory operation instructions.
After the reset signal is generated, the value of this register becomes "00H".
Figure 4-5
Format of the system clock with the PLL Control Register (PLLCR).
Address: 40020C02H
after reset:
00H R/W
symbol
PLLCR
PLLSRSEL
The input clock source of the PLL is selected
0
Select the high-speed internal oscillator clock F
IH
as the input clock source for
the PLL
1
Select the external master system clock F
MX
as the input clock source for the
PLL
PLLD1
PLLD0
PLL Divider selection
0
0
No Dividers
0
1
Divide-by-2
1
x
Divide-by-4
PLLM
PLL multiplication option
0
12 times
1
16 times
PLLON
PLL work enable
0
PLL turns off
1
PLL turns on
When using PLL as the system clock, the clock structure is shown in the following figure, where m is 12/16,
which is determined by the setting value of PLLM, and n is 1/2/4, which is determined by the setting value of
PLD1/PLLD0.
Figure 4-6
The clock structure of the PLL when the system clock is used
internal high speed clock
f
IH
external primary system
clock f
MX
selector
m
frequency
multiplicati
on
n
frequency
division
system clock
PLL
f
PLL
Note: To use the PLL as the system clock, the bit4 (MCM0) and bit6 (CSS) of the CKC register must be set to
0.
7
6
5
4
3
2
2
1
0
PLLSRSEL
0
0
0
PLLD1
PLLD0
PLLM
PLLON