mc9s12ne64 Freescale Semiconductor, Inc, mc9s12ne64 Datasheet - Page 59

• Manufacturer Part Number: mc9s12ne64
• Description: Hcs12 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

1.3
The clock and reset generator provides the internal clock signals for the core and all peripheral modules.
Figure 1-5
chapter for details on clock generation.
1.4
There are eight possible modes of operation available on the MC9S12NE64. Each mode has an associated
default memory map and external bus configuration.
1.4.1
The operating mode out of reset is determined by the states of the MODC, MODB, and MODA pins during
reset. The MODC, MODB, and MODA bits in the MODE register show the current operating mode and
provide limited mode switching during operation. The states of the MODC, MODB, and MODA pins are
latched into these bits on the rising edge of the RESET signal. The ROMCTL signal allows the setting of
the ROMON bit in the MISC register thus controlling whether the internal FLASH is visible in the memory
map. ROMON = 1 means the FLASH is visible in the memory map. The state of the ROMCTL pin is
latched into the ROMON bit in the MISC register on the rising edge of the RESET signal.
Freescale Semiconductor
System Clock Description
Modes of Operation
shows the clock connections from the CRG to all modules. See the CRG block description
Chip Configuration Summary
EXTAL
XTAL
CRG
Figure 1-5. Clock Connections
MC9S12NE64 Data Sheet, Rev 1.0
bus clock
oscillator clock
core clock
VREG_PHY
S12_CORE
FLASH
EPHY
RAM
EMAC
ATD
TIM
PIM
SCI
SPI
IIC
System Clock Description
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