MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 76

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

Low-Power Modes
Computer Operating Properly Module (COP)
Wait Mode
Stop Mode
Direct Memory Access Module (DMA)
Wait Mode
Stop Mode
MC68HC708XL36
76
The COP remains active in wait mode. To prevent a COP reset during
wait mode, periodically clear the COP counter in a CPU interrupt routine
or a DMA service routine.
Stop mode turns off the CGMXCLK input to the COP and clears the COP
prescaler. Service the COP immediately before entering or after exiting
stop mode to ensure a full COP timeout period after entering or exiting
stop mode.
The STOP bit in the configuration register (CONFIG) enables the STOP
instruction. To prevent inadvertently turning off the COP with a STOP
instruction, disable the STOP instruction by clearing the STOP bit.
If enabled by the DMAWE bit in the DMA status and control register, the
DMA remains active in wait mode. The DMA can transfer data to and
from peripherals while the MCU remains in wait mode.
If the WAIT instruction occurs during a DMA transfer while DMAWE is
set, the DMA transfer continues to completion. If the DMAWE bit is clear,
a WAIT instruction suspends the current DMA transfer. If the DMA
priority bit (DMAP) is set, the suspended transfer resumes when the
MCU exits wait mode.
The DMA is inactive during stop mode. A STOP instruction suspends
any DMA transfer in progress. If an external interrupt brings the MCU out
of stop mode and the DMA priority bit (DMAP) is set, the suspended
DMA transfer resumes. If a reset brings the MCU out of stop mode, the
transfer is aborted.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
Low-Power Modes
MOTOROLA
4-lp24_e