MC908MR16CFUE Datasheet, PDF (77/282 Pages) Freescale Semiconductor, Inc – On-chip programming firmware for use with host personal computer, Clock generator module (CGM)

COP Control Register
6.3.6 COPD (COP Disable)
The COPD signal reflects the state of the COP disable bit (COPD) in the configuration register (CONFIG).
See Chapter 5 Configuration Register (CONFIG).
6.4 COP Control Register
The COP control register is located at address $FFFF and overlaps the reset vector. Writing any value to
$FFFF clears the COP counter and starts a new timeout period. Reading location $FFFF returns the low
byte of the reset vector.
Address: $FFFF
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Low byte of reset vector
Write:
Clear COP counter
Reset:
Unaffected by reset
Figure 6-3. COP Control Register (COPCTL)
6.5 Interrupts
The COP does not generate CPU interrupt requests.
6.6 Monitor Mode
The COP is disabled in monitor mode when V_HI is present on the IRQ pin or on the RST pin.
6.7 Wait Mode
The WAIT instruction puts the MCU in low power-consumption standby mode.
The COP continues to operate during wait mode.
6.8 Stop Mode
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.
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Freescale Semiconductor
77