MC908QL4 FREESCALE [Freescale Semiconductor, Inc], MC908QL4 Datasheet - Page 129

• Manufacturer Part Number: MC908QL4
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

13.7.1 Wait Mode
In wait mode, the CPU clocks are inactive while the peripheral clocks continue to run.
the timing for wait mode entry.
A module that is active during wait mode can wake up the CPU with an interrupt if the interrupt is enabled.
Stacking for the interrupt begins one cycle after the WAIT instruction during which the interrupt occurred.
In wait mode, the CPU clocks are inactive. Refer to the wait mode subsection of each module to see if the
module is active or inactive in wait mode. Some modules can be programmed to be active in wait mode.
Wait mode can also be exited by a reset (or break in emulation mode). A break interrupt during wait mode
sets the SIM break stop/wait bit, SBSW, in the break status register (BSR). If the COP disable bit, COPD,
in the configuration register is 0, then the computer operating properly module (COP) is enabled and
remains active in wait mode.
Figure 13-15
Freescale Semiconductor
and
EXITSTOPWAIT
NOTE: EXITSTOPWAIT = RST pin OR CPU interrupt
ADDRESS BUS
ADDRESS BUS
1. RST is only available if the RSTEN bit in the CONFIG1 register is set.
ADDRESS BUS
NOTE: Previous data can be operand data or the WAIT opcode, depending on the last instruction.
BUSCLKX4
DATA BUS
DATA BUS
Figure 13-16
DATA BUS
RST
R/W
(1)
Figure 13-16. Wait Recovery from Internal Reset
$A6
$A6
WAIT ADDR
Figure 13-15. Wait Recovery from Interrupt
show the timing for wait recovery.
Figure 13-14. Wait Mode Entry Timing
$6E0B
$A6
$6E0B
$A6
PREVIOUS DATA
MC68HC908QL4 Data Sheet, Rev. 7
$A6
$A6
WAIT ADDR + 1
CYCLES
$6E0C
32
$01
NEXT OPCODE
$00FF
CYCLES
$0B
32
SAME
$00FE
$6E
SAME
RST VCT H
$00FD
SAME
RST VCT L
$00FC
SAME
Figure 13-14
Low-Power Modes
shows
129