mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 76

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Internal Clock Generator Module (ICG)
7.3.5 Clock Selection Circuit
The clock selection circuit, shown in
output clock (CGMXCLK) and the timebase clock (TBMCLK) from either the internal clock (ICLK) or the
external clock (ECLK). The clock selection circuit also contains a divide-by-two circuit which creates the
clock generator output clock (CGMOUT), which generates the bus clocks.
76
ESTBCLK
ECGEN
CMON
ECLK
IREF
RESET
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
NAME
NAME
ECGON
ECLK
EOFF
IOFF
ICLK
V
CS
NAME
NAME
SS
Figure 7-7. Clock Selection Circuit Block Diagram
Figure 7-6. External Clock Activity Detector
D
CK
DFFRS
CONFIGURATION (OR MOR) REGISTER BIT
TOP LEVEL SIGNAL
R
S
CONFIGURATION (OR MOR) REGISTER BIT
TOP LEVEL SIGNAL
Q
Figure
CK
7-7, contains two clock switches which generate the oscillator
SELECT
ICLK
ECLK
IOFF
EOFF
FORCE_I
FORCE_E
SELECT
ICLK
ECLK
IOFF
EOFF
FORCE_I
FORCE_E
1/4
R
Q
SYNCHRONIZING
SYNCHRONIZING
SWITCHER
SWITCHER
D
CK
CLOCK
CLOCK
DFFRR
R
R
Q
OUTPUT
OUTPUT
NAME
NAME
NAME
NAME
DIV2
MODULE SIGNAL
MODULE SIGNAL
REGISTER BIT
REGISTER BIT
CGMXCLK
CGMOUT
TBMCLK
EGGS
EOFF
Freescale Semiconductor