MC68HC908AZ32ACFU MOTOROLA [Motorola, Inc], MC68HC908AZ32ACFU Datasheet - Page 338

• Manufacturer Part Number: MC68HC908AZ32ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Programmable Interrupt Timer (PIT)
20.6.1 Wait Mode
20.6.2 Stop Mode
20.7 PIT During Break Interrupts
Advance Information
338
The PIT remains active after the execution of a WAIT instruction. In wait
mode the PIT registers are not accessible by the CPU. Any enabled CPU
interrupt request from the PIT can bring the MCU out of wait mode.
If PIT functions are not required during wait mode, reduce power
consumption by stopping the PIT before executing the WAIT instruction.
The PIT is inactive after the execution of a STOP instruction. The STOP
instruction does not affect register conditions or the state of the PIT
counter. PIT operation resumes when the MCU exits stop mode after an
external interrupt.
A break interrupt stops the PIT 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
on page 134).
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.
Freescale Semiconductor, Inc.
For More Information On This Product,
Programmable Interrupt Timer (PIT)
Go to: www.freescale.com
SIM Break Flag Control Register
68HC908AZ32A — Rev 0.0
MOTOROLA