System Integration Module (SIM)
Technical Data
MC68HC908AB32
—
Rev. 1.0
124
System Integration Module (SIM)
MOTOROLA
8.7 Low-Power Modes
Executing the STOP or WAIT instruction puts the MCU in a low-power-
consumption mode for standby situations. The SIM holds the CPU in a
non-clocked state. The operation of each of these modes is described
below. Both STOP and WAIT clear the interrupt mask (I) in the condition
code register, allowing interrupts to occur.
8.7.1 Wait Mode
In wait mode, the CPU clocks are inactive while the peripheral clocks
continue to run.
shows 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. A break interrupt
during wait mode sets the SIM break STOP/WAIT bit, SBSW, in the SIM
break status register (SBSR). If the COP disable bit, COPD, in the
configuration register 1 (CONFIG1) is 0, then the computer operating
properly (COP) module is enabled and remains active in wait mode.
Figure 8-12. Wait Mode Entry Timing
and
show the timing for wait recovery.
WAIT ADDR + 1
SAME
SAME
IAB
IDB
PREVIOUS DATA
NEXT OPCODE
SAME
WAIT ADDR
SAME
R/W
NOTE: Previous data can be operand data or the WAIT opcode, depending on the
last instruction.
Summary of Contents for MC68HC908AB32
Page 1: ...MC68HC908AB32 D REV 1 0 MC68HC908AB32 HCMOS Microcontroller Unit TECHNICAL DATA ...
Page 2: ......
Page 68: ...FLASH Memory Technical Data MC68HC908AB32 Rev 1 0 68 FLASH Memory MOTOROLA ...
Page 84: ...EEPROM Technical Data MC68HC908AB32 Rev 1 0 84 EEPROM MOTOROLA ...
Page 390: ...Ordering Information Technical Data MC68HC908AB32 Rev 1 0 390 Ordering Information MOTOROLA ...
Page 391: ......