7.4.2.3 Illegal Opcode Reset

The SIM decodes signals from the CPU to detect illegal instructions. An illegal instruction sets the ILOP bit in the reset status register (RSR) and causes a reset.

If the stop enable bit, STOP, in the mask option register is logic zero, the SIM treats the STOP instruction as an illegal opcode and causes an illegal opcode reset. The SIM actively pulls down the RST pin for all internal reset sources.

7.4.2.4 Illegal Address Reset

An opcode fetch from an unmapped address generates an illegal address reset. The SIM verifies that the CPU is fetching an opcode prior to asserting the ILAD bit in the reset status register (RSR) and resetting the MCU. A data fetch from an unmapped address does not generate a reset. The SIM actively pulls down the RST pin for all internal reset sources.

7.4.2.5 Universal Serial Bus Reset

The USB module will detect a reset signal on the bus by the presence of an extended SE0 at the USB data pins of the upstream port. The reset signaling is specified to be present for a minimum of 10 ms. An active device (powered and not in the suspend state) seeing a single-ended zero on its USB data inputs for more than 2.5s may treat that signal as a reset, but must have interpreted the signaling as a reset within 5.5 s. For USB device, an SE0 condition between 4 and 8 low speed bit times or 32 and 64 high speed bit times represents a valid USB reset. After the reset is removed, the device will be in the attached, but not yet addressed or configured state (refer to Section 9.1 of the USB specification). The device must be able to accept device address via a SET_ADDRESS command (refer to section 9.4 of the USB specification) no later than 10 ms after the reset is removed.

Reset can wake a device from the suspended mode. A device may take up to 10 ms to wake up from the suspended state.

Advance Information

MC68HC(7)08KH12 Rev. 1.1

 

 

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Freescale Semiconductor MC68HC08KH12 manual Illegal Opcode Reset, Illegal Address Reset, Universal Serial Bus Reset

MC68HC08KH12 specifications

The Freescale Semiconductor MC68HC08KH12 is a versatile microcontroller that has gained popularity in various embedded systems applications. Part of the HC08 family, this microcontroller combines a robust architecture with comprehensive on-chip features, making it suitable for a wide range of applications ranging from industrial control to consumer electronics.

One of the main features of the MC68HC08KH12 is its 8-bit architecture, which provides an optimal balance between performance and power efficiency. It operates at clock speeds of up to 2 MHz, allowing for efficient execution of instructions while maintaining low power consumption. The microcontroller is designed to operate over a voltage range of 2.7 to 5.5 volts, making it adaptable to various system requirements.

The MC68HC08KH12 is equipped with 1 Kbyte of RAM and 12 Kbytes of ROM, which allows for substantial program and data storage. The on-chip memory helps reduce the need for external components, simplifying the design of embedded systems and enhancing reliability. With a wide range of I/O options, including 26 general-purpose I/O pins, the microcontroller provides flexibility in interfacing with sensors, actuators, and other devices.

In terms of technologies, the MC68HC08KH12 features an advanced instruction set that enhances programming efficiency. It supports basic arithmetic operations, bit manipulation, and control transfer instructions, making it suitable for a variety of computational tasks. The integrated timers, analog-to-digital converters, and serial communication interfaces, including UART, provide the necessary tools for real-time control and data exchange with peripheral devices.

Another characteristic of the MC68HC08KH12 is its low power mode capabilities, which allow it to enter a sleep state during periods of inactivity. This feature is essential in battery-powered applications, where minimizing power consumption is crucial for extending operational life.

Overall, the Freescale Semiconductor MC68HC08KH12 stands out as a reliable microcontroller that combines performance, flexibility, and power efficiency. Its extensive features and technologies enable engineers to design robust embedded systems that meet the demands of modern applications. As a result, the MC68HC08KH12 remains a valuable choice for developers seeking a highly functional yet cost-effective microcontroller solution.