mc68hc05p18a Freescale Semiconductor, Inc, mc68hc05p18a Datasheet - Page 52

• Manufacturer Part Number: mc68hc05p18a
• Description: Mc68hc05p18a Hcmos Microcontroller Unit
• Manufacturer: Freescale Semiconductor, Inc

Operating Modes
6.4.1 STOP Instruction
6.4.1.1 Stop Mode
Technical Data
NOTE:
The STOP instruction can result in one of two modes of operation,
depending on the mask option.
Execution of the STOP instruction without conversion to halt places the
MCU in its lowest power consumption mode. In stop mode, the internal
oscillator is turned off, halting all internal processing, including the COP
watchdog timer. The RC oscillator that feeds the electrically erasable
programmable read-only memory (EEPROM) and the A/D converter is
also stopped. Execution of the STOP instruction automatically clears the
I bit in the condition code register so that the IRQ external interrupt is
enabled. All other registers and memory remain unaltered. All
input/output lines remain unchanged.
The MCU can be brought out of the stop mode only by:
When exiting stop mode, the internal oscillator resumes after a 4064
PH2 clock cycle oscillator stabilization delay.
Execution of the STOP instruction without conversion to halt (via mask
option) causes the oscillator to stop, and therefore disable the COP
watchdog timer. If the COP watchdog timer is to be used, stop mode
should be changed to halt mode by selecting the appropriate mask
option.
1. If the stop conversion to halt mask option is not chosen, the STOP
2. If the stop conversion to halt mask option is chosen, the STOP
•
•
•
Freescale Semiconductor, Inc.
For More Information On This Product,
instruction behaves like a normal STOP instruction in the
M68HC05 Family and places the MCU in stop mode.
instruction behaves like a WAIT instruction (with the exception of
a brief delay at startup) and places the MCU in halt mode.
An IRQ external interrupt
Port A external interrupt, if selected as a mask option
An externally generated reset
Go to: www.freescale.com
Operating Modes
MC68HC05P18A