Low-Power Mode, Reset | Freescale Semiconductor MC68HC908MR32

System Integration Module (SIM)

14.5.1.2 Software Interrupt (SWI) Instruction

The software interrupt (SWI) instruction is a non-maskable instruction that causes an interrupt regardless of the state of the interrupt mask

(I bit) in the condition code register.

14.5.2 Reset

All reset sources always have equal and highest priority and cannot be arbitrated.

14.6 Low-Power Mode

Executing the WAIT instruction puts the MCU in a low power-consumption mode for standby situations. The SIM holds the CPU in a non-clocked state. WAIT clears the interrupt mask (I) in the condition code register, allowing interrupts to occur.

14.6.1 Wait Mode

In wait mode, the CPU clocks are inactive while the peripheral clocks continue to run. Figure 14-11shows 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. 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. If the COP disable bit, COPD, in the configuration register is logic 0, then the computer operating properly module (COP) is enabled and remains active in wait mode.

IAB

WAIT ADDR

WAIT ADDR + 1

SAME

IDB

PREVIOUS DATA

NEXT OPCODE

SAME

R/W

Note: Previous data can be operand data or the WAIT opcode, depending on the last instruction.

Figure 14-11. Wait Mode Entry Timing

Figure 14-12and Figure 14-13show the timing for wait recovery.

IAB

$6E0B

$6E0C

$00FF

$00FE

$00FD

$00FC

IDB

$A6

$01

$0B

$6E

EXITSTOPWAIT

Note: EXITSTOPWAIT = RST pin OR CPU interrupt

Figure 14-12. Wait Recovery from Interrupt

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

190	Freescale Semiconductor

MC68HC908MR16, MC68HC908MR32 specifications

Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are part of the popular HC08 family, designed primarily for embedded applications. These microcontrollers are particularly favored in automotive, industrial, and consumer product sectors due to their reliability and versatility.

One of the standout features of the MC68HC908MR series is its CMOS technology, which enhances performance while minimizing power consumption. This makes these microcontrollers suitable for battery-operated devices. They operate at a maximum clock frequency of 2 MHz and offer a 16-bit architecture, providing a solid balance between processing power and efficiency.

The MC68HC908MR32 variant is equipped with 32KB of flash memory, which allows for the storage of complex programs and extensive data handling. In contrast, the MC68HC908MR16 features 16KB of flash memory, making it ideal for simpler applications. Both microcontrollers also come with 1KB of RAM, enabling efficient data processing and real-time operations.

Another significant characteristic of these microcontrollers is their integrated peripherals. They come with multiple input/output (I/O) pins, which allow for connectivity with various sensors and actuators. The built-in timer systems offer precise timing control for automotive and industrial applications, while the Analog-to-Digital Converter (ADC) provides essential conversion capabilities for various analog signals.

For communication purposes, the MC68HC908MR series includes a serial communication interface, enabling easy integration with other devices and systems. This versatility facilitates the development of complex systems that require interaction with external components.

Security is another crucial aspect of these microcontrollers. They have built-in fail-safe mechanisms to ensure reliable operation under various conditions, making them suitable for critical systems. Additionally, their robust architecture helps to safeguard against potential disruptions or attacks.

In summary, Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are key players in the embedded systems landscape. Their blend of power efficiency, integrated features, and scalability ensures they remain relevant for a wide array of applications, making them a favored choice among engineers and developers looking for dependable solutions in a competitive market.

Freescale Semiconductor MC68HC908MR32 Low-Power Mode, Reset, Software Interrupt SWI Instruction

Models: MC68HC908MR16 MC68HC908MR32