h8s-2628 Renesas Electronics Corporation., h8s-2628 Datasheet - Page 531

• Manufacturer Part Number: h8s-2628
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

This LSI has an on-chip clock pulse generator that generates the system clock ( ), the bus master
clock, and internal clocks. The clock pulse generator consists of an oscillator, PLL circuit, clock
selection circuit, medium-speed clock divider, and bus master clock selection circuit. A block
diagram of the clock pulse generator is shown in figure 20.1.
The frequency can be changed by means of the PLL circuit. Frequency changes are performed by
software by settings in the low-power control register (LPWRCR) and system clock control
register (SCKCR).
CPG0100B_000020020900
EXTAL
XTAL
Legend:
LPWRCR: Low-power control register
SCKCR:
oscillator
Clock
System clock control register
Figure 20.1 Block Diagram of Clock Pulse Generator
Section 20 Clock Pulse Generator
( 1, 2, 4)
PLL circuit
LPWRCR
STC1, STC0
selection
circuit
Clock
System clock
to
pin
Rev. 3.00 Oct 04, 2005 page 491 of 598
clock divider
Medium-
speed
Section 20 Clock Pulse Generator
peripheral modules
Internal clock to
/32 to
/2
selection
SCKCR
master
REJ09B0155-0300
circuit
clock
Bus
Bus master clock
to CPU and DTC
SCK2 to SCK0