Rev. 1.0, 09/02, page 467 of 568
Section 20 Clock Pulse Generator
This LSI has an on-chip clock pulse generator that generates the system clock (
φ
), 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.
EXTAL
XTAL
SCK2 to SCK0
SCKCR
STC1, STC0
LPWRCR
Legend
LPWRCR : Low-power control register
SCKCR
: System clock control register
Clock
oscillator
PLL circuit
(
×
1,
×
2,
×
4)
Clock
selection
circuit
System clock
to
φ
pin
Internal clock to
peripheral modules
Bus master clock
to CPU and DTC
Medium-
speed
clock divider
Bus
master
clock
selection
circuit
φ
/2 to
φ
/32
f
Figure 20.1 Block Diagram of Clock Pulse Generator
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
Содержание H8S/2627
Страница 22: ...Rev 1 0 09 02 page xx of xxxvi Index 565 ...
Страница 30: ...Rev 1 0 09 02 page xxviii of xxxiv ...
Страница 36: ...Rev 1 0 09 02 page xxxiv of xxxiv Table 23 9 Flash Memory Characteristics 561 ...
Страница 82: ...Rev 1 0 09 02 page 46 of 568 ...
Страница 88: ...Rev 1 0 09 02 page 52 of 568 ...
Страница 98: ...Rev 1 0 09 02 page 62 of 568 ...
Страница 156: ...Rev 1 0 09 02 page 120 of 568 ...
Страница 390: ...Rev 1 0 09 02 page 354 of 568 ...
Страница 480: ...Rev 1 0 09 02 page 444 of 568 ...
Страница 512: ...Rev 1 0 09 02 page 476 of 568 ...
Страница 527: ...Rev 1 0 09 02 page 491 of 568 21 8 5 Writing to MSTPCR MSTPCR should only be written to by the CPU ...
Страница 528: ...Rev 1 0 09 02 page 492 of 568 ...
Страница 580: ...Rev 1 0 09 02 page 544 of 568 ...