MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 58

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Resets and Interrupts
Introduction
Resets
Effects
External Reset
Internal Reset
MC68HC708XL36
58
Resets and interrupts are responses to exceptional events during
program execution. A reset reinitializes the MCU to its startup condition.
An interrupt vectors the program counter to a service routine.
A reset returns the MCU to a known startup condition and begins
program execution from a user-defined memory location.
A reset:
A logic 0 applied to the RST pin for a time, t
reset. An external reset sets the PIN bit in the reset status register.
Sources:
All internal reset sources pull the RST pin low for 32 CGMXCLK cycles
to allow resetting of external devices. The MCU is held in reset for an
additional 32 CGMXCLK cycles after releasing the RST pin.
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Freescale Semiconductor, Inc.
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Immediately stops the operation of the instruction being executed.
Initializes certain control and status bits.
Loads the program counter with a user-defined reset vector
address from locations $FFFE and $FFFF.
Selects CGMXCLK divided by four as the bus clock.
Power-on reset
COP
Low-voltage inhibit
Illegal opcode
Illegal address
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Resets and Interrupts
IRL
, generates an external
MOTOROLA
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