9.2
Overview of CPG
9.2.1
CPG Block Diagram
A block diagram of the on-chip clock pulse generator is shown in figure 9.1.
Clock pulse generator
Divider 1
CAP1
× 1
Internal
clock (Iφ)
Cycle = Icyc
PLL circuit 1
(× 1, 2, 3, 4,
6)
× 1/2
× 1/3
× 1/4
× 1/6
CKIO
Cycle = Bcyc
CAP2
XTAL
Divider 2
× 1
× 1/2
× 1/3
× 1/4
× 1/6
Crystal
oscillator
Peripheral
clock (Pφ)
Cycle = Pcyc
PLL circuit 2
(× 1, 4)
EXTAL
CPG control unit
Clock frequency
control circuit
Standby control
circuit
Standby
control
MD2
MD1
MD0
FRQCR
STBCR
Bus interface
Internal bus
Legend
FRQCR: Frequency control register STBCR: Standby control register
Figure 9.1 Block Diagram of Clock Pulse Generator
Rev. 5.00, 09/03, page 204 of 760