
8. Clock Generation Circuits
Figure 8.6
PLC0 Register, PLC1 Register
b7
1
0
1
b6 b5 b4
b1
b2
b3
PLL Control Register 0 (1, 2, 5, 6)
Symbol
PLC0
Address
0026h
Bit Symbol
Bit Name
RW
PLC00
After Reset
0001 X010b
NOTES:
1. Set the PLC0 register after the PRC0 bit in the PRCR register is set to 1 (write enable).
2. If the PM21 bit in the PM2 register is set to 1 (disable a clock change), a write to the PLC0 register has no effect.
3. Set bits PLC02 to PLC00 while the PLC07 bit is 0.
4. Set the CM17 bit in the CM1 register to 0 (main clock as CPU clock source) and then the PLC07 bit to 0 to enter wait or
stop mode.
5. Set registers PLC0 and PLC1 simultaneously in 16-bit units.
6. The PLC0 register can be written only once except the PLC07 bit.
b0
Function
Programmable counter
select bits(3)
PLC01
PLC02
PLL synthesizer multiplies the main clock by
the following variables.
b2 b1 b0
1 0 0: Multiply-by-4
1 1 0: Multiply-by-6
0 0 0: Multiply-by-8
Do not set to values other than the above
(b3)
(b4)
RW
(b5)
RW
Reserved bit
Set to 1
PLL Control Register 1(1, 2, 3, 4, 5)
b7
0
1
0
b6 b5 b4
b1
b2
b3
Syambol
PLC1
Address
0027h
Bit Symbol
Bit Name
RW
(b0)
After Reset
00h
b0
Function
(b1)
RW
Reserved bit
(b6)
PLC07
Reserved bit
Set to 0
0: PLL stopped
1: PLL run
Operation enable bit(4)
RW
(b7-b2)
RW
Reserved bit
Reserved bits
Set to 0
Set to 1
Set to 0
RW
NOTES:
1. Set the PLC1 register after the PRC0 bit in the PRCR register is set to 1 (write enable).
2. If the PM21 bit in the PM2 register is set to 1 (disable a clock change), a write to the PLC1 register has no effect.
3. Set the PLC1 register while the PLC07 bit in the PLC0 register is set to 0 (PLL off).
4. Set registers PLC0 and PLC1 simultaneously in 16-bit units.
5. The PLC1 register can be written only once.
When read, the content is undefined
Reserved bit