MC68HC908GR16 Datasheet, PDF (255/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Timer Interface Module (TIM)
Low-Power Modes
18.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby
modes.
18.6.1 Wait Mode
The TIM remains active after the execution of a WAIT instruction. In wait mode, the
TIM registers are not accessible by the CPU. Any enabled CPU interrupt request
from the TIM can bring the MCU out of wait mode.
If TIM functions are not required during wait mode, reduce power consumption by
stopping the TIM before executing the WAIT instruction.
18.6.2 Stop Mode
The TIM is inactive after the execution of a STOP instruction. The STOP instruction
does not affect register conditions or the state of the TIM counter. TIM operation
resumes when the MCU exits stop mode after an external interrupt.
18.7 TIM During Break Interrupts
A break interrupt stops the TIM counter.
The system integration module (SIM) controls whether status bits in other modules
can be cleared during the break state. The BCFE bit in the SIM break flag control
register (SBFCR) enables software to clear status bits during the break state. See
15.7.3 Break Flag Control Register.
To allow software to clear status bits during a break interrupt, write a logic 1 to the
BCFE bit. If a status bit is cleared during the break state, it remains cleared when
the MCU exits the break state.
To protect status bits during the break state, write a logic 0 to the BCFE bit. With
BCFE at logic 0 (its default state), software can read and write I/O registers during
the break state without affecting status bits. Some status bits have a 2-step
read/write clearing procedure. If software does the first step on such a bit before
the break, the bit cannot change during the break state as long as BCFE is at logic
0. After the break, doing the second step clears the status bit.
18.8 I/O Signals
Port D shares four of its pins with the TIM. The four TIM channel I/O pins are
T1CH0, T1CH1, T2CH0, and T2CH1 as described in 18.3 Pin Name
Conventions.
Each channel I/O pin is programmable independently as an input capture pin or an
output compare pin. T1CH0 and T2CH0 can be configured as buffered output
compare or buffered PWM pins.
MC68HC908GR16 — Rev. 1.0
MOTOROLA
Timer Interface Module (TIM)
For More Information On This Product,
Go to: www.freescale.com
Data Sheet
255