MC68HC912D60 Datasheet, PDF (169/432 Pages) Freescale Semiconductor, Inc – M68HC12 Microcontrollers

Freescale Semiconductor, Inc.
Clock Functions
Clock Divider Chains
BCSP BCSS
1:x
PHASE
LOCK
LOOP
PLLCLK
SYSCLK
T CLOCK
÷2
GENERATOR
TCLKs
TO CPU
EXTAL
EXTALi
REDUCED
CONSUMPTION
OSCILLATOR
EXTALi
XTAL
EXTALi
BCSP BCSS
0:0
BCSP BCSS
0:1
CLKSRC = 1
CLKSRC = 0
SLOW MODE
CLOCK
DIVIDER
SLWCLK
÷2
÷2
E AND P
CLOCK
GENERATOR
ECLK
PCLK
TO
BUSES,
SPI,
PWM,
ATD0, ATD1
SYNC
SYNC
MCS = 0
MCS = 1
CLKSW = 0
TO
MSCAN
TO
MCLK _{SCI0, SCI1,}
ECT
XCLK
TO
RTI, COP
TO CAL
CLKSW = 1
BDMCLK
TO BDM
TO CLOCK
MONITOR
Figure 12-6. Clock Generation Chain
Bus clock select bits BCSP and BCSS in the clock select register
(CLKSEL) determine which clock drives SYSCLK for the main system
including the CPU and buses. BCSS has no effect if BCSP is set. During
68HC(9)12D60 — Rev 4.0
MOTOROLA
Clock Functions
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Advance Information
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